Romania's Simona Halep celebrates after defeating Poland's Iga Swiatek in their fourth round match at the Australian Open tennis championship in Melbourne, Australia, Sunday, Feb. 14, 2021.(AP Photo/Hamish Blair)

Romania's Simona Halep hits a forehand return to United States' Serena Williams during their quarterfinal match at the Australian Open tennis championship in Melbourne, Australia, Tuesday, Feb. 16, 2021.(AP Photo/Andy Brownbill)

Simona Halep of Romania returns the ball to Anastasia Potapova of Russia during the women's singles Round of 32 tennis match of the WTA 500 VTB Kremlin Cup 2021 International Tennis Tournament at the Irina Viner-Usmanova Gymnastics Palace on October 19, 2021 in Moscow, Russia. VTB Kremlin Cup 2021 International Tennis Tournament, Moscow, Russia - 19 Oct 2021,Image: 638721480, License: Rights-managed, Restrictions: RESTRICTED TO EDITORIAL USE, Model Release: no, Credit line: Profimedia

Novak DJOKOVIC (SRB) plays Taylor FRITZ (USA) on Rod Laver Arena during Day 5 of the Australian Open at Melbourne Park on Saturday, February 13, 2021. MANDATORY PHOTO CREDIT Tennis Australia/ ROB PREZIOSO

Novak Djokovic during his semi-final match Australian Open Tennis, Day Eleven, Melbourne Park, Australia - 18 Feb 2021,Image: 591782027, License: Rights-managed, Restrictions: , Model Release: no

Jennifer Brady celebrates victory after winning her Semi Final Match Australian Open Tennis, Day Eleven, Melbourne Park, Australia - 18 Feb 2021,Image: 591738865, License: Rights-managed, Restrictions: , Model Release: no

MELBOURNE, VIC - FEBRUARY 18: Naomi Osaka of Japan returns the ball during the semifinals of the 2021 Australian Open on February 18 2021, at Melbourne Park in Melbourne, Australia.,Image: 591723472, License: Rights-managed, Restrictions: FOR EDITORIAL USE ONLY. Icon Sportswire (A Division of XML Team Solutions) reserves the right to pursue unauthorized users of this image. If you violate our intellectual property you may be liable for: actual damages, loss of income, and profits you derive from the use of this image, and, where appropriate, the costs of collection and/or statutory damages up to $150,000 (USD)., Model Release: no