Novak Djokovic of Serbia walks onto the court before the start of the men's singles final against Stefanos Tsitsipas of Greece at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Ng Han Guan)
Stefanos Tsitsipas of Greece waves as he walks onto the court before the start of the men's singles final against Novak Djokovic of Serbia at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Ng Han Guan)
Novak Djokovic of Serbia, right, and Stefanos Tsitsipas of Greece pose with the winners trophy before the start of the men's singles final at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Ng Han Guan)
Novak Djokovic of Serbia plays a backhand return to Stefanos Tsitsipas of Greece during the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Dita Alangkara)
Stefanos Tsitsipas of Greece plays a forehand return to Novak Djokovic of Serbia during the men's singles final at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Ng Han Guan)
Fans carrying Serbian flags cheer for Novak Djokovic of Serbia as he plays against Stefanos Tsitsipas of Greece during the men's singles final at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Ng Han Guan)
Stefanos Tsitsipas of Greece gestures as he talks with chair umpire Louise Azemar Engzell during his men's singles final match against Novak Djokovic of Serbia at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Dita Alangkara)
Stefanos Tsitsipas of Greece plays a backhand return to Novak Djokovic of Serbia during the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Mark Baker)
Novak Djokovic of Serbia plays a backhand return to Stefanos Tsitsipas of Greece during the men's singles final at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Ng Han Guan)
Novak Djokovic of Serbia reacts after defeating Stefanos Tsitsipas of Greece in the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Mark Baker)
Novak Djokovic of Serbia, left, meets Stefanos Tsitsipas of Greece at the net after Djokovic won the men's singles final at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Asanka Brendon Ratnayake)
Novak Djokovic of Serbia celebrates after defeating Stefanos Tsitsipas of Greece in the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Aaron Favila)
Novak Djokovic of Serbia, center, celebrates defeating Stefanos Tsitsipas of Greece in the men's singles final at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Asanka Brendon Ratnayake)
Novak Djokovic of Serbia, center, celebrates with his team including his mother, Dijana, left, after defeating Stefanos Tsitsipas of Greece in the men's singles final at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Asanka Brendon Ratnayake)
Novak Djokovic of Serbia cries after defeating Stefanos Tsitsipas of Greece in the men's singles final at the Australian Open tennis championships in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Asanka Brendon Ratnayake)
Novak Djokovic of Serbia celebrates in the stands with his support team after defeating Stefanos Tsitsipas of Greece in the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Aaron Favila)
Novak Djokovic of Serbia lifts the Norman Brookes Challenge Cup after defeating Stefanos Tsitsipas of Greece in the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 29, 2023. (AP Photo/Ng Han Guan)
Novak Djokovic, left, of Serbia holds the Norman Brookes Challenge Cup as he makes a post match speech after defeating Stefanos Tsitsipas of Greece in the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 29, 2023.(AP Photo/Dita Alangkara)
Novak Djokovic of Serbia lifts the Norman Brookes Challenge Cup after defeating Stefanos Tsitsipas of Greece in the men's singles final at the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 29, 2023.(AP Photo/Dita Alangkara)