Emma Raducanu of Great Britain hits a backhand against Maria Sakkari of Greece (not pictured) on day eleven of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Aryna Sabalenka of Belarus hits to Barbora Krejcikova of Czech Republic on day nine of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Shuai Zhang of China, left, and Samantha Stosur of Australia pose with the women's doubles championship trophy on day fourteen of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Daniil Medvedev of Russia celebrates after his match against Novak Djokovic of Serbia (not pictured) in the men's singles final on day fourteen of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Daniil Medvedev of Russia celebrates with the championship trophy after his match against Novak Djokovic of Serbia (not pictured) in the men's singles final on day fourteen of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Alexander Zverev of Germany hits to Jannik Sinner of Italy on day eight of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Elina Svitolina the Ukraine celebrates a winner against Simona Halep (not pictured) of Romania on day seven of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Frances Tiafoe of the United States reacts during his loss to Felix Auger-Aliassime of Canada (not pictured) on day seven of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Maria Sakkari of Greece hits to Bianca Andreescu of Canada on day eight of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Jannik Sinner of Italy hits to Alexander Zverev of Germany on day eight of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Novak Djokovic of Serbia hits to Matteo Berrettini of Italy on day ten of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Desirae Krawczyk of the United States, right, and Joe Salisbury of Great Britain hug as they win the mixed doubles final on day twelve of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

An American flag is unfurled during a ceremony observing the 20th anniversary of the 9/11 terror attacks prior to the match between Leylah Fernandez of Canada and Emma Raducanu of Great Britain (both not pictured) in the women's singles final on day thirteen of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports Image used for illustrative purpose.

Daniil Medvedev of Russia serves against Botic van de Zandschulp of the Netherlands (not pictured) on day nine of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Geoff Burke-USA TODAY Sports TPX IMAGES OF THE DAY

Emma Raducanu of Great Britain celebrates after match point against Maria Sakkari of Greece (not pictured) on day eleven of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Diego Schwartzman of Argentina gestures after losing a point against Botic Van De Zandschulp of the Netherlands (not pictured) on day seven of the 2021 U.S. Open tennis tournament at USTA Billie King National Tennis Center. Mandatory Credit: Geoff Burke-USA TODAY Sports

Bianca Andreescu of Canada (left) takes a drink during a change as fans cheer her on in the third set against Maria Sakkari of Greece on day eight of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Novak Djokovic of Serbia celebrates after his match against Alexander Zverev of Germany (not pictured) on day twelve of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Emma Raducanu of Great Britain celebrates with the championship trophy after her match against Leylah Fernandez of Canada (not pictured) in the women's singles final on day thirteen of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Leylah Fernandez of Canada, right, shakes hands with Naiomi Osaka of Japan after a third round match on day five of the 2021 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Jerry Lai-USA TODAY Sports