NEW YORK, NY - SEPTEMBER 07:  Stan Wawrinka of Switzerland returns a shot to Donald Young of the United States during their Men's Singles Fourth Round match on Day Eight of the 2015 US Open at the USTA Billie Jean King National Tennis Center on September 7, 2015 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Streeter Lecka/Getty Images)