錦織圭 全豪オープン(01 of70)
Open Image ModalKei Nishikori of Japan celebrates after winning over David Ferrer of Spain in their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Lee Jin-man) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(02 of70)
Open Image ModalKei Nishikori of Japan, right, shakes hands with David Ferrer of Spain after winning their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Rob Griffith) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(03 of70)
Open Image ModalKei Nishikori of Japan celebrates after defeating David Ferrer of Spain in their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Lee Jin-man) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(04 of70)
Open Image ModalKei Nishikori of Japan celebrates after winning over David Ferrer of Spain in their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Rob Griffith) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(05 of70)
Open Image ModalKei Nishikori of Japan signs autographs for fans after defeating David Ferrer of Spain in their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Lee Jin-man) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(06 of70)
Open Image ModalKei Nishikori of Japan celebrates after winning over David Ferrer of Spain in their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Rob Griffith) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(07 of70)
Open Image ModalKei Nishikori of Japan makes a forehand return to David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Rob Griffith) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(08 of70)
Open Image ModalKei Nishikori of Japan celebrates a point won against David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Rob Griffith) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(09 of70)
Open Image ModalKei Nishikori of Japan makes a forehand return to David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Lee Jin-man) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(10 of70)
Open Image ModalKei Nishikori of Japan celebrates a point won against David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Rob Griffith) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(11 of70)
Open Image ModalKei Nishikori of Japan plays a shot to David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Lee Jin-man) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(12 of70)
Open Image ModalKei Nishikori of Japan makes a backhand return to David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Rob Griffith) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(13 of70)
Open Image ModalKei Nishikori of Japan makes a forehand return to David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Rob Griffith) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(14 of70)
Open Image ModalKei Nishikori of Japan makes a backhand return to David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Lee Jin-man) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(15 of70)
Open Image ModalKei Nishikori of Japan makes a forehand return to David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Lee Jin-man) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(16 of70)
Open Image ModalKei Nishikori of Japan makes a forehand return to David Ferrer of Spain during their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Monday, Jan. 26, 2015. (AP Photo/Rob Griffith) (credit:ASSOCIATED PRESS)
錦織圭 全豪オープン(17 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 26: Kei Nishikori of Japan and David Ferrer of Spain at the net after Nishikori won their fourth round match during day eight of the 2015 Australian Open at Melbourne Park on January 26, 2015 in Melbourne, Australia. (Photo by Patrick Scala/Getty Images) (credit:Patrick Scala via Getty Images)
錦織圭 全豪オープン(18 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 26: Kei Nishikori of Japan plays a backhand in his fourth round match against David Ferrer of Spain during day eight of the 2015 Australian Open at Melbourne Park on January 26, 2015 in Melbourne, Australia. (Photo by Clive Brunskill/Getty Images) (credit:Clive Brunskill via Getty Images)
錦織圭 全豪オープン(19 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 26: Kei Nishikori of Japan plays a backhand in his fourth round match against David Ferrer of Spain during day eight of the 2015 Australian Open at Melbourne Park on January 26, 2015 in Melbourne, Australia. (Photo by Clive Brunskill/Getty Images) (credit:Clive Brunskill via Getty Images)
錦織圭 全豪オープン(20 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 26: Kei Nishikori of Japan plays a backhand in his fourth round match against David Ferrer of Spain during day eight of the 2015 Australian Open at Melbourne Park on January 26, 2015 in Melbourne, Australia. (Photo by Clive Brunskill/Getty Images) (credit:Clive Brunskill via Getty Images)
錦織圭 全豪オープン(21 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Spain\'s David Ferrer on day eight of the 2015 Australian Open tennis tournament in Melbourne on January 26, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
2015 Australian Open - Day 6(22 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan celebrates winning his third round match against Steve Johnson of the United States during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Hannah Peters/Getty Images) (credit:Hannah Peters via Getty Images)
2015 Australian Open - Day 7(23 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 25: Kei Nishikori of Japan in action in a practice session during day seven of the 2015 Australian Open at Melbourne Park on January 25, 2015 in Melbourne, Australia. (Photo by Michael Dodge/Getty Images) (credit:Michael Dodge via Getty Images)
2015 Australian Open - Day 7(24 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 25: Kei Nishikori of Japan in action in a practice session during day seven of the 2015 Australian Open at Melbourne Park on January 25, 2015 in Melbourne, Australia. (Photo by Michael Dodge/Getty Images) (credit:Michael Dodge via Getty Images)
TENNIS-AUS-OPEN(25 of70)
Open Image ModalJapan\'s Kei Nishikori gestures as he celebrates after victory in his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
TENNIS-AUS-OPEN(26 of70)
Open Image ModalJapan\'s Kei Nishikori changes his shirt during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(27 of70)
Open Image ModalKei Nishikori of Japan celebrates his victory over Ivan Dodig of Croatia in their men\'s singles match on day four of the 2015 Australian Open tennis tournament in Melbourne on January 22, 2015. AFP PHOTO / MANAN VATSYAYANA \n-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read MANAN VATSYAYANA/AFP/Getty Images) (credit:MANAN VATSYAYANA via Getty Images)
TENNIS-AUS-OPEN(28 of70)
Open Image ModalJapan\'s Kei Nishikori celebrates after victory in his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
TENNIS-AUS-OPEN(29 of70)
Open Image ModalJapan\'s Kei Nishikori celebrates after victory in his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
2015 Australian Open - Day 6(30 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan serves in his third round match against Steve Johnson of the United States during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Hannah Peters/Getty Images) (credit:Hannah Peters via Getty Images)
TENNIS-AUS-OPEN(31 of70)
Open Image ModalJapan\'s Kei Nishikori celebrates after victory in his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
2015 Australian Open - Day 7(32 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 25: Kei Nishikori of Japan in action in a practice session during day seven of the 2015 Australian Open at Melbourne Park on January 25, 2015 in Melbourne, Australia. (Photo by Michael Dodge/Getty Images) (credit:Michael Dodge via Getty Images)
TENNIS-AUS-OPEN(33 of70)
Open Image ModalJapan\'s Kei Nishikori reacts during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / PAUL CROCK -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read PAUL CROCK/AFP/Getty Images) (credit:PAUL CROCK via Getty Images)
2015 Australian Open - Day 4(34 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 22: Kei Nishikori of Japan returns ball in tennis match against Ivan Dodig of Croatia during day four of the 2015 Australian Open at Melbourne Park on January 22, 2015 in Melbourne, Australia. (Photo by Recep Sakar/Anadolu Agency/Getty Images) (credit:Anadolu Agency via Getty Images)
2015 Australian Open - Day 5(35 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 23: Kei Nishikori of Japan plays a forehand in a practice session during day five of the 2015 Australian Open at Melbourne Park on January 23, 2015 in Melbourne, Australia. (Photo by Patrick Scala/Getty Images) (credit:Patrick Scala via Getty Images)
2015 Australian Open - Day 5(36 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 23: Kei Nishikori of Japan plays a forehand in a practice session during day five of the 2015 Australian Open at Melbourne Park on January 23, 2015 in Melbourne, Australia. (Photo by Patrick Scala/Getty Images) (credit:Patrick Scala via Getty Images)
2015 Australian Open - Day 5(37 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 23: Kei Nishikori of Japan looks on in a practice session during day five of the 2015 Australian Open at Melbourne Park on January 23, 2015 in Melbourne, Australia. (Photo by Patrick Scala/Getty Images) (credit:Patrick Scala via Getty Images)
2015 Australian Open - Day 5(38 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 23: Kei Nishikori of Japan serves in a practice session during day five of the 2015 Australian Open at Melbourne Park on January 23, 2015 in Melbourne, Australia. (Photo by Patrick Scala/Getty Images) (credit:Patrick Scala via Getty Images)
2015 Australian Open - Day 6(39 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan plays a forehand in a practice session during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Patrick Scala/Getty Images) (credit:Patrick Scala via Getty Images)
2015 Australian Open - Day 6(40 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan plays a forehand in a practice session during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Patrick Scala/Getty Images) (credit:Patrick Scala via Getty Images)
TENNIS-AUS-OPEN(41 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(42 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(43 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(44 of70)
Open Image ModalJapan\'s Kei Nishikori reacts during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(45 of70)
Open Image ModalJapan\'s Kei Nishikori reacts during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(46 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(47 of70)
Open Image ModalJapan\'s Kei Nishikori serves during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
TENNIS-AUS-OPEN(48 of70)
Open Image ModalJapan\'s Kei Nishikori serves during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
TENNIS-AUS-OPEN(49 of70)
Open Image ModalJapan\'s Kei Nishikori serves during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
TENNIS-AUS-OPEN(50 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(51 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(52 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(53 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(54 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(55 of70)
Open Image ModalJapan\'s Kei Nishikori changes his shirt during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(56 of70)
Open Image ModalJapan\'s Kei Nishikori gestures during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(57 of70)
Open Image ModalJapan\'s Kei Nishikori reacts during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(58 of70)
Open Image ModalJapan\'s Kei Nishikori serves during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / WILLIAM WEST-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read WILLIAM WEST/AFP/Getty Images) (credit:WILLIAM WEST via Getty Images)
TENNIS-AUS-OPEN(59 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
TENNIS-AUS-OPEN(60 of70)
Open Image ModalJapan\'s Kei Nishikori hits a return during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / PAUL CROCK -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read PAUL CROCK/AFP/Getty Images) (credit:PAUL CROCK via Getty Images)
TENNIS-AUS-OPEN(61 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
TENNIS-AUS-OPEN(62 of70)
Open Image ModalJapan\'s Kei Nishikori walks between points during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / PAUL CROCK -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read PAUL CROCK/AFP/Getty Images) (credit:PAUL CROCK via Getty Images)
TENNIS-AUS-OPEN(63 of70)
Open Image ModalJapan\'s Kei Nishikori plays a shot during his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
2015 Australian Open - Day 6(64 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan serves in his third round match against Steve Johnson of the United States during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Hannah Peters/Getty Images) (credit:Hannah Peters via Getty Images)
2015 Australian Open - Day 6(65 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan serves in his third round match against Steve Johnson of the United States during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Hannah Peters/Getty Images) (credit:Hannah Peters via Getty Images)
2015 Australian Open - Day 6(66 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan wipes his face in his third round match against Steve Johnson of the United States during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Hannah Peters/Getty Images) (credit:Hannah Peters via Getty Images)
TENNIS-AUS-OPEN(67 of70)
Open Image ModalJapan\'s Kei Nishikori celebrates after victory in his men\'s singles match against Steve Johnson of the US on day six of the 2015 Australian Open tennis tournament in Melbourne on January 24, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE (Photo credit should read GREG WOOD/AFP/Getty Images) (credit:GREG WOOD via Getty Images)
2015 Australian Open - Day 6(68 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan celebrates winning his third round match against Steve Johnson of the United States during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Hannah Peters/Getty Images) (credit:Hannah Peters via Getty Images)
2015 Australian Open - Day 6(69 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan celebrates winning his third round match against Steve Johnson of the United States during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Hannah Peters/Getty Images) (credit:Hannah Peters via Getty Images)
2015 Australian Open - Day 6(70 of70)
Open Image ModalMELBOURNE, AUSTRALIA - JANUARY 24: Kei Nishikori of Japan reacts in his third round match against Steve Johnson of the United States during day six of the 2015 Australian Open at Melbourne Park on January 24, 2015 in Melbourne, Australia. (Photo by Hannah Peters/Getty Images) (credit:Hannah Peters via Getty Images)