Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 Serena Williams of the U.S. in action during her first round match against Germany's Laura Siegemund.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 7, 2021 Spain's Rafael Nadal during a practice session before the Australian Open.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 Germany's Alexander Zverev reacts as a bird flies by during his first round match against Marcos Giron of the U.S.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 9, 2021 Sofia Kenin of the U.S. in action during her first round match against Australia's Maddison Inglis.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 9, 2021 Cori Gauff of the U.S. in action during her first round match against Switzerland's Jil Teichmann.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 9, 2021 Spain's Rafael Nadal during his first round match against Serbia's Laslo Djere.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 9, 2021 Russia's Daniil Medvedev in action during his first round match against Canada's Vasek Pospisil.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 9, 2021 Ukraine's Elina Svitolina during her first round match against Czech Republic's Marie Bouzkova.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 9, 2021 Tennys Sandgren of the U.S. in action during his first round match against Australia's Alex de Minaur.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 Austria's Dominic Thiem in action during his first round match against Kazakhstan's Mikhail Kukushkin.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 Germany's Alexander Zverev breaks his racket during his first round match against Marcos Giron of the U.S.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 Fans watch the first round match between Czech Republic's Petra Kvitova and Belgium's Greet Minnen. Crowd capacity for this years event has been capped at 30,000 per day following the outbreak of the coronavirus disease (COVID-19).

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 Canada's Denis Shapovalov in action during his first round match against Italy's Jannik Sinner.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 9, 2021 Spain's Rafael Nadal in action during his first round match against Serbia's Laslo Djere.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 General view of Australia's Lizette Cabrera in action during her first round match against Romania's Simona Halep.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 Germany's Laura Siegemund reacts during her first round match against Serena Williams of the U.S.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 Australia's Nick Kyrgios during his first round match against Portugal's Frederico Ferreira Silva.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 8, 2021 Serbia's Novak Djokovic celebrates winning his first round match against France's Jeremy Chardy.

Tennis - Australian Open - Melbourne Park, Melbourne, Australia, February 9, 2021 Spain's Rafael Nadal tries to make a butterfly fly from his hand during his first round match against Serbia's Laslo Djere.