NEW YORK, NY - SEPTEMBER 01:  Karolina Pliskova of the Czech Republic reacts against Montserrat Gonzalez of Paraguay during her second round Women's Singles match on Day Four of the 2016 US Open at the USTA Billie Jean King National Tennis Center on September 1, 2016 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Michael Reaves/Getty Images)