see more

NEW YORK, NY - SEPTEMBER 06: (L-R) Kei Nishikori of Japan poses with Novak Djokovic of Serbia prior to their men's singles semifinal match on Day Thirteen of the 2014 US Open at the USTA Billie Jean King National Tennis Center on September 6, 2014 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Julian Finney/Getty Images)

NEW YORK, NY - SEPTEMBER 06:  (L-R) Kei Nishikori of Japan poses with Novak Djokovic of Serbia prior to their men's singles semifinal match on Day Thirteen of the 2014 US Open at the USTA Billie Jean King National Tennis Center on September 6, 2014 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Julian Finney/Getty Images)