Denis Shapovalov of Canada celebrates after match point against Sebastian Korda of the United States. Danielle Parhizkaran-USA TODAY Sports
Novak Djokovic hits the ball against Damir Dzumhur on day one of the 2020 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Robert Deutsch-USA TODAY Sports
Damir Dzumhur hits the ball against Novak Djokovic on day one of the 2020 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Robert Deutsch-USA TODAY Sports
Stands at Arthur Ashe Stadium sit nearly empty as Novak Djokovic, of Serbia, left, returns to Damir Dzumhur, of Bosnia and Herzegovina, during the first round of the US Open tennis championships, in New York. AP Photo
Novak Djokovic, of Serbia, returns to Damir Dzumhur, of Bosnia and Herzegovina, during the first round of the US Open tennis championships, in New York. AP
Damir Dzumhur, of Bosnia and Herzegovina, returns to Novak Djokovic, of Serbia, during the first round of the US Open tennis championships, in New York. AP
Novak Djokovic tries to return the ball against Damir Dzumhur (BIH) on day one of the 2020 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Robert Deutsch-USA TODAY Sports
Reilly Opelka of the United States returns a shot during his Men's Singles first round match against David Goffin of Belgium. AFP
David Goffin of Belgium returns a shot during his Men's Singles first round match against Reilly Opelka of the United States. AFP
Steve Johnson of the United States lunges for a ball during his Men's Singles first round match against John Isner of the United States. AFP
Alexander Bublik of Kazakhstan returns shot during his Men's Singles round one match against Kyle Edmund of Great Britain. AFP
Soonwoo Kwon of Korea waits for a serve during his Men's Singles first round match against Thai-Son Kwiatkowski of the United States. AFP
Yasutaka Uchiyama of Japan reacts after a point against Pablo Carreno Busta of Spain. Danielle Parhizkaran-USA TODAY Sports.
Denis Shapovalov of Canada celebrates after match point against Sebastian Korda of the United States. Danielle Parhizkaran-USA TODAY Sports
Novak Djokovic hits the ball against Damir Dzumhur on day one of the 2020 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Robert Deutsch-USA TODAY Sports
Damir Dzumhur hits the ball against Novak Djokovic on day one of the 2020 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Robert Deutsch-USA TODAY Sports
Stands at Arthur Ashe Stadium sit nearly empty as Novak Djokovic, of Serbia, left, returns to Damir Dzumhur, of Bosnia and Herzegovina, during the first round of the US Open tennis championships, in New York. AP Photo
Novak Djokovic, of Serbia, returns to Damir Dzumhur, of Bosnia and Herzegovina, during the first round of the US Open tennis championships, in New York. AP
Damir Dzumhur, of Bosnia and Herzegovina, returns to Novak Djokovic, of Serbia, during the first round of the US Open tennis championships, in New York. AP
Novak Djokovic tries to return the ball against Damir Dzumhur (BIH) on day one of the 2020 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Robert Deutsch-USA TODAY Sports
Reilly Opelka of the United States returns a shot during his Men's Singles first round match against David Goffin of Belgium. AFP
David Goffin of Belgium returns a shot during his Men's Singles first round match against Reilly Opelka of the United States. AFP
Steve Johnson of the United States lunges for a ball during his Men's Singles first round match against John Isner of the United States. AFP
Alexander Bublik of Kazakhstan returns shot during his Men's Singles round one match against Kyle Edmund of Great Britain. AFP
Soonwoo Kwon of Korea waits for a serve during his Men's Singles first round match against Thai-Son Kwiatkowski of the United States. AFP
Yasutaka Uchiyama of Japan reacts after a point against Pablo Carreno Busta of Spain. Danielle Parhizkaran-USA TODAY Sports.
Denis Shapovalov of Canada celebrates after match point against Sebastian Korda of the United States. Danielle Parhizkaran-USA TODAY Sports