France's Benoit Paire has tested positive for COVID-19 and pulled out of the US Open starting on Monday, French sports daily L'Equipe reported.
Paire, seeded 17th at the Grand Slam event, had been scheduled to play Poland's Kamil Majchrzak in the first round at Flushing Meadows on Tuesday.
Paire's name no longer appeared on the list of seeds on the tournament website on Sunday and the men's draw showed Majchrzak would play Spain's Marcel Granollers.
A United States Tennis Association spokesman said he could "only confirm that a player has tested positive and has been withdrawn".
The 31-year-old Paire arrived in New York to play the Western & Southern Open last week, a tune-up for the US Open, but he did not complete his first-round match against Croatia's Borna Coric.
Paire appeared unwell during the match and asked for a doctor in the opening set before retiring in the second while trailing 6-0 1-0.
L'Equipe reported that fellow Frenchmen Richard Gasquet, Adrian Mannarino, Gregoire Barrere and Edouard Roger Vasselin were also asked to self-isolate in their hotel rooms after Paire's positive test.
The US Open is being played without fans and in a biosecure bubble due to the pandemic, but several high-ranking players skipped the tournament due to coronavirus concerns.
World number three Dominic Thiem told reporters he still felt confident in the level of safety at the event.
"There is no safer place in the world right now than here," said Thiem. "Maybe you can lock yourself somewhere in a cave or something, I don't know, in the middle of the sea. Otherwise, it's super safe here.
"Still something can happen, as you could see with Benoit. We hope that nobody else is infected," he added.
Thiem was among those who apologised in June for the way players conducted themselves at Novak Djokovic’s Adria Tour exhibition event after which four players tested positive for the novel coronavirus.