The participation of two players in the US Open is in doubt after their physio was the only person out of 1,400 to test positive for coronavirus.
Argentina's Guido Pella, ranked 35th, and Bolivian world number 94 Hugo Dellien have been placed in quarantine following Juan Galvan's result.
The pair are out of the Cincinnati Masters, which starts on Friday and is also being played at Flushing Meadows.
The US Open takes place at the same New York venue from 31 August.
Both tournaments will be held without fans and players will have to follow strict measures inside the United States Tennis Association's (USTA) safety bubble.