Alexander Zverev, right, of Germany embraces Novak Djokovic of Serbia after Djokovic retired from their semifinal match at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2025. (AP Photo/Ng Han Guan)

Alexander Zverev of Germany serves to Novak Djokovic of Serbia during their semifinal match at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2025. (AP Photo/Ng Han Guan)

Jannik Sinner of Italy reacts during his semifinal match against Ben Shelton of the U.S. at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2025. (AP Photo/Ng Han Guan)

Jannik Sinner of Italy plays a backhand return to Ben Shelton of the U.S. during their semifinal match at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2025. (AP Photo/Ng Han Guan)

Jannik Sinner of Italy signs autographs after defeating Ben Shelton of the U.S. in their semifinal match at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2025. (AP Photo/Manish Swarup)

Jannik Sinner of Italy receives medical treatment during his semifinal match against Ben Shelton of the U.S. at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2025. (AP Photo/Ng Han Guan)

Alexander Zverev of Germany plays a forehand return to Novak Djokovic of Serbia during their semifinal match at the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 24, 2025. (AP Photo/Ng Han Guan)