MASON, OHIO - AUGUST 15: Roger Federer of Switzerland serves to Andrey Rublev of Russia during Day 6 of the Western and Southern Open at Lindner Family Tennis Center on August 15, 2019 in Mason, Ohio. (Photo by Rob Carr/Getty Images)
MASON, OHIO - AUGUST 15: Roger Federer of Switzerland serves to Andrey Rublev of Russia during Day 6 of the Western and Southern Open at Lindner Family Tennis Center on August 15, 2019 in Mason, Ohio. (Photo by Rob Carr/Getty Images)