NEW YORK, NY - SEPTEMBER 09: Kei Nishikori (L) of Japan and Stan Wawrinka of Switzerland prepare for their Men's Singles Semifinal Match on Day Twelve of the 2016 US Open at the USTA Billie Jean King National Tennis Center on September 9, 2016 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Elsa/Getty Images)
