The USTA National Tennis Center has had its first positive coronavirus case ahead of the Western & Southern Open and US Open events.
An individual who is not a player has tested positive, is asymptomatic and must isolate for at least 10 days, with a contact tracing process now initiated.
There have been 1,400 tests administered on those within the bubble since August 13.
"The USTA has worked with the ATP Tour and WTA Tour to create a controlled environment for the 2020 Western & Southern Open and US Open," read a USTA statement on Tuesday.
"The USTA, together with its medical advisors and infectious disease specialist from the Mount Sinai Health System, confirmed a positive test result for an individual.
"In accordance with New York State Department of Health requirements, and in alignment with CDC guidelines and the Tournament health and safety protocols, the individual has been advised that they must isolate for at least 10 days.
"In addition, contact tracing has been initiated to determine if anyone must quarantine for 14 days."
The Western & Southern Open, usually held in Cincinnati, begins at the New York site this week, followed by the US Open on August 31.
Multiple high-profile players have withdrawn from what will be the second grand slam event of the year, amid the uncertainty caused by the coronavirus pandemic.
The defending champions of both draws, Rafael Nadal and Bianca Andreescu, are not playing, although Novak Djokovic and Serena Williams are among the stars who do plan to participate.