Maximilian Marterer Pictures
NEW YORK, NY - AUGUST 28: Maximilian Marterer of Germany reacts during his men's singles first round match against Kei Nishikori of Japan on Day Two of the 2018 US Open at the USTA Billie Jean King National Tennis Center on August 28, 2018 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Elsa/Getty Images)