Pablo Carreno Busta, of Spain, adjusts his wristbands during a quarterfinal men's tennis match against Daniil Medvedev, of the Russian Olympic Committee, at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Pablo Carreno Busta, of Spain, serves to Daniil Medvedev, of the Russian Olympic Committee, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, of the Russian Olympic Committee, returns to Pablo Carreno Busta, of Spain, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, of the Russian Olympic Committee, serves to Pablo Carreno Busta, of Spain, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, of the Russian Olympic Committee, serves to Pablo Carreno Busta, of Spain, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, of the Russian Olympic Committee, returns to Pablo Carreno Busta, of Spain, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, of the Russian Olympic Committee, returns to Pablo Carreno Busta, of Spain, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, of the Russian Olympic Committee, returns to Pablo Carreno Busta, of Spain, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Pablo Carreno Busta, of Spain, returns to Daniil Medvedev, of the Russian Olympic Committee, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Pablo Carreno Busta, of Spain, returns to Daniil Medvedev, of the Russian Olympic Committee, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, right, of the Russian Olympic Committee, serves to Pablo Carreno Busta, of Spain, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Pablo Carreno Busta, of Spain, serves to Daniil Medvedev, of the Russian Olympic Committee, during the quarterfinal round of the men's tennis competition at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, of the Russian Olympic Committee, wipes sweat from his face during a quarterfinal men's tennis match against Pablo Carreno Busta, of Spain, at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, of the Russian Olympic Committee, wipes sweat from his face during a quarterfinal men's tennis match against Pablo Carreno Busta, of Spain, at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Pablo Carreno Busta, of Spain, walks on the court during a quarterfinal round men's tennis match against Daniil Medvedev, of the Russian Olympic Committee, at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Daniil Medvedev, of the Russian Olympic Committee, walks on the court during a quarterfinal men's tennis match against Pablo Carreno Busta, of Spain, at the 2020 Summer Olympics, Thursday, July 29, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)