Russia's Daniil Medvedev hits a backhand to Serbia's Novak Djokovic during the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 21, 2021. (AP Photo/Hamish Blair)

Serbia's Novak Djokovic takes a bandage off after defeating Russia's Daniil Medvedev in the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 21, 2021.(AP Photo/Mark Dadswell)

Serbia's Novak Djokovic reacts after winning a point against Russia's Daniil Medvedev during the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 21, 2021.(AP Photo/Andy Brownbill)

Russia's Daniil Medvedev raises his racket as if to smash it on the court while playing Serbia's Novak Djokovic during the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 21, 2021. (AP Photo/Hamish Blair)

Serbia's Novak Djokovic hits a backhand to Russia's Daniil Medvedev during the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 21, 2021. (AP Photo/Hamish Blair)

Russia's Daniil Medvedev hits a forehand return to Serbia's Novak Djokovic during the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 21, 2021.(AP Photo/Andy Brownbill)

Spectators stand for the Australian national anthem ahead of the men's singles final Serbia's Novak Djokovic and Russia's Daniil Medvedev at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 21, 2021.(AP Photo/Andy Brownbill)

Serbia's Novak Djokovic celebrates after defeating Russia's Aslan Karatsev in their semifinal match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Feb. 18, 2021.(AP Photo/Andy Brownbill)

Russia's Daniil Medvedev reacts after winning a point against Greece's Stefanos Tsitsipas during their semifinal match at the Australian Open tennis championship in Melbourne, Australia, Friday, Feb. 19, 2021.(AP Photo/Andy Brownbill)

Croatia's Ivan Dodig, right, and Slovakia's Filip Polasek hold their trophy aloft after defeating Rajeev Ram of the US and Britain's Joe Salisbury in the men's doubles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 21, 2021.(AP Photo/Andy Brownbill)

Slovakia's Filip Polasek, left, and Croatia's Ivan Dodig, second left, pose with their trophy after defeating Rajeev Ram, right, of the US and Britain's Joe Salisbury in the men's doubles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 21, 2021.(AP Photo/Andy Brownbill)