Andrea Petkovic Pictures
NEW YORK, NEW YORK - AUGUST 31: Andrea Petkovic of Germany serves the ball during her Women's Singles third round match against Elise Mertens of Belgium on day six of the 2019 US Open at the USTA Billie Jean King National Tennis Center on August 31, 2019 in Queens borough of New York City. (Photo by Matthew Stockman/Getty Images)