Nishikori of Japan hits a return to Djokovic of Serbia during their semi-final match at the 2014 U.S....
Kei Nishikori of Japan hits a return to Novak Djokovic of Serbia during their semi-final match at the 2014 U.S. Open tennis tournament in New York, September 6, 2014. REUTERS/Mike Segar (UNITED STATES - Tags: SPORT TENNIS)