NEW YORK, NY - AUGUST 31:  Elias Ymer of Sweden returns a shot against  Diego Schwartzman of Argentina during their Men's Singles First Round match on Day One of the 2015 US Open at the USTA Billie Jean King National Tennis Center on August 31, 2015 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Clive Brunskill/Getty Images)