Olympic Tournament Men Singles

Hugo Dellien, left, of Bolivia, speaks with Novak Djokovic, of Serbia, after losing to Djokovic during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Hugo Dellien, left, of Bolivia, speaks with Novak Djokovic, of Serbia, after losing to Djokovic during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, returns to Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, reacts after defeating Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, reacts after defeating Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, returns to Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, wipes his face during the tennis competition against Hugo Dellien, of Bolivia, at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

A necklace dangles from Novak Djokovic's neck as he returns to Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, serves to Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, reacts after defeating Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, returns to Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, returns to Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, wipes sweat from his brow as he competes Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, reacts after defeating Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Novak Djokovic, of Serbia, reacts after defeating Hugo Dellien, of Bolivia, during the tennis competition at the 2020 Summer Olympics, Saturday, July 24, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)