Serbia's Novak Djokovic reacts during his match against Italy's Salvatore Caruso, at the Italian Open tennis tournament in Rome, Wednesday, Sept. 16, 2020. (Alfredo Falcone/LaPresse via AP)

Serbia's Novak Djokovic serves the ball to Italy's Salvatore Caruso, at the Italian Open tennis tournament in Rome, Wednesday, Sept. 16, 2020. (Alfredo Falcone/LaPresse via AP)

Serbia's Novak Djokovic returns the ball to Italy's Salvatore Caruso, at the Italian Open tennis tournament in Rome, Wednesday, Sept. 16, 2020. (Alfredo Falcone/LaPresse via AP)

Italy's Salvatore Caruso returns the ball to Serbia's Novak Djokovic, at the Italian Open tennis tournament in Rome, Wednesday, Sept. 16, 2020. (Alfredo Falcone/LaPresse via AP)

Romania's Simona Halep returns the ball to Italy's Jasmine Paolini during their match at the Italian Open tennis tournament in Rome, Wednesday, Sept. 16, 2020. (Alfredo Falcone/LaPresse via AP)

Greece's Stefanos Tsitsipas wipes his face during his match with Italy's Jannik Sinner, at the Italian Open tennis tournament in Rome, Wednesday, Sept. 16, 2020. (Alfredo Falcone/LaPresse via AP)

Belarus' Viktoria Azarenka returns the ball to United States' Venus Williams during their match at the Italian Open tennis tournament in Rome, Wednesday, Sept. 16, 2020. (Alfredo Falcone/LaPresse via AP)

The stands around the Central Court of the Foro Italico are empty during a match between Serbia's Novak Djokovic and Italy's Salvatore Caruso, at the Italian Open tennis tournament in Rome, Wednesday, Sept. 16, 2020. The tournament at the Foro Italico was rescheduled from May because of the pandemic and is being played without fans in attendance. (Alfredo Falcone/LaPresse via AP)

Italy's Jannik Sinner returns the ball to Greece's Stefanos Tsitsipas, at the Italian Open tennis tournament in Rome, Wednesday, Sept. 16, 2020. (Alfredo Falcone/LaPresse via AP)