Barclays ATP World Tour Finals - Previews(01 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Kei Nishikori of Japan poses for a photo during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(02 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Novak Djokovic of Serbia, Stan Wawrinka of Switzerland, Tomas Berdych of Czech Republic, Marin Cilic of Croatia, Roger Federer of Switzerland, Andy Murray of Great Britain, Kei Nishikori of Japan, Milos Raonic of Canada pose for a photo as they travel along the thames during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(03 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Chris Kermode Executive Chairman & President ATP talks to guests with players Novak Djokovic of Serbia, Stan Wawrinka of Switzerland, Tomas Berdych of Czech Republic, Marin Cilic of Croatia, Roger Federer of Switzerland, Andy Murray of Great Britain, Kei Nishikori of Japan and Milos Raonic of Canada as they travel along the thames during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(04 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Kei Nishikori of Japan meets guests during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(05 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Kei Nishikori of Japan poses for a photo during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(06 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Kei Nishikori of Japan poses for a photo during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(07 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Novak Djokovic of Serbia, Stan Wawrinka of Switzerland, Tomas Berdych of Czech Republic, Marin Cilic of Croatia, Roger Federer of Switzerland, Andy Murray of Great Britain, Kei Nishikori of Japan, Milos Raonic of Canada with Chris Kermode Executive Chairman & President ATP pose for a photo as they travel along the thames during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(08 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Novak Djokovic of Serbia, Stan Wawrinka of Switzerland, Tomas Berdych of Czech Republic, Marin Cilic of Croatia, Roger Federer of Switzerland, Andy Murray of Great Britain, Kei Nishikori of Japan and Milos Raonic of Canada take a group selfie as they travel along the thames during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(09 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Novak Djokovic of Serbia, Stan Wawrinka of Switzerland, Tomas Berdych of Czech Republic, Marin Cilic of Croatia, Roger Federer of Switzerland, Andy Murray of Great Britain, Kei Nishikori of Japan and Milos Raonic of Canada take a group selfie as they travel along the thames during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(10 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Tomas Berdych of the Czech Republic takes a group selfie of Stan Wawrinka of Switzerland,Milos Raonic of Canada,Novak Djokovic of Serbia,Kei Nishikori of Japan,Andy Murray of Great Britain,Roger Federer of Switzerland and Marin Cilic of Croatia after the mens singles official group shot had been taken prior to the start of the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Clive Brunskill/Getty Images) (credit:Clive Brunskill via Getty Images)
Barclays ATP World Tour Finals - Previews(11 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: L-R Stan Wawrinka of Switzerland,Milos Raonic of Canada,Tomas Berdych of Czech Republic,Novak Djokovic of Serbia,Kei Nishikori of Japan,Andy Murray of Great Britain,Roger Federer of Switzerland and Marin Cilic of Croatia all pose for the mens singles official group shot prior to the start of the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Clive Brunskill/Getty Images) (credit:Clive Brunskill via Getty Images)
Barclays ATP World Tour Finals - Previews(12 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Kei Nishikori of Japan talks to the media during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)
Barclays ATP World Tour Finals - Previews(13 of13)
Open Image ModalLONDON, ENGLAND - NOVEMBER 07: Kei Nishikori of Japan talks to the media during the Barclays ATP World Tour Finals tennis previews at the O2 Arena on November 7, 2014 in London, England. (Photo by Julian Finney/Getty Images) (credit:Julian Finney via Getty Images)