WASHINGTON, DC - AUGUST 02: Kei Nishikori of Japan returns a shot against Sam Querrey of the United States on Day 3 during the Citi Open at Rock Creek Tennis Center on August 2, 2021 in Washington, DC. (Photo by Mitchell Layton/Getty Images)
WASHINGTON, DC - AUGUST 02: Kei Nishikori of Japan returns a shot against Sam Querrey of the United States on Day 3 during the Citi Open at Rock Creek Tennis Center on August 2, 2021 in Washington, DC. (Photo by Mitchell Layton/Getty Images)