MASON, OHIO - AUGUST 14: Kei Nishikori of Japan returns a shot to Yoshihito Nishioka of Japan during the Western & Southern Open at Lindner Family Tennis Center on August 14, 2019 in Mason, Ohio. (Photo by Matthew Stockman/Getty Images)
MASON, OHIO - AUGUST 14: Kei Nishikori of Japan returns a shot to Yoshihito Nishioka of Japan during the Western & Southern Open at Lindner Family Tennis Center on August 14, 2019 in Mason, Ohio. (Photo by Matthew Stockman/Getty Images)