Benoit Paire tested positive for coronavirus and was removed from the US Open men's draw.
Paire's name was removed from the US Open website's official draw and replaced with Marcel Granollers, who is set to face Kamil Majchrzak in a first-round match next week.
The US Tennis Association said the asymptomatic player has been advised to follow state and tournament health and safety protocols requiring isolation for at least 10 days.
Contact tracing has been initiated to determine if anyone else must quarantine for 14 days as a result of being around the player involved.
L'Equipe said fellow French players Richard Gasquet, Gregoire Barrere, Edouard Roger-Vasselin and Adrian Mannarino have been confined to their hotel rooms at the tournament until further notice.
News of the positive test comes after players have been practicing and playing a tuneup event, the ATP and WTA Western and Southern Open, usually staged in Cincinnati, in the same quarantine bubble where the US Open begins Monday without spectators.
USTA officials aren't expected to confirm any individual player's test results under US medical privacy laws.
Paire had arrived in the US on August 18 and numerous coronavirus tests had returned negative results.
However, he was forced to retire from his first round match in the Western and Southern Open against Borna Coric after complaining of feeling unwell.
