FILE - In this Sept. 12, 2021, file photo, Novak Djokovic, of Serbia, returns a shot to Daniil Medvedev, of Russia, during the men's singles final of the U..S. Open tennis championships in New York. Djokovic will not play in the U.S. Open, as expected, because he is not vaccinated against COVID-19 and thus is not allowed to travel to the United States. Djokovic announced his withdrawal from the year’s last Grand Slam tournament on Twitter on Thursday, Aug. 25, 2022, hours before the draw for the event was revealed. (AP Photo/John Minchillo, File)