Novak_Djokovic_221

Serbia's Novak Djokovic returns the ball during an exhibition tournament in Zadar, Croatia, Sunday, June 21, 2020. Tennis player Grigor Dimitrov says he has tested positive for COVID-19 and his announcement led to the cancellation of an exhibition event in Croatia where Novak Djokovic was scheduled to play on Sunday. (AP Photo/Zvonko Kucelin)