Nick Watney has become the first golfer to test positive for coronavirus since the PGA Tour's resumption last week, necessitating the American's withdrawal from the RBC Heritage ahead of his second round.
The PGA said Watney was exhibiting symptoms of the virus on Friday prior to arriving at Harbour Town Golf Links, a few days after he and the rest of the field, plus caddies and essential personnel, returned blanket negative tests.
A subsequent test came back positive and the PGA revealed it is "implementing its response plan" and attempting to track down and work with those who have had close contact with Watney.
The PGA said in a statement: "Nick Watney has withdrawn from the RBC Heritage prior to the second round after testing positive for Covid-19.
"On Friday, prior to arriving at the tournament, he indicated he had symptoms consistent with the illness and after consulting with a physician, was administered a test and found to be positive.
"Nick will have the PGA Tour's full support throughout his self-isolation and recovery period.
"Watney, who travelled privately to Hilton Head Island for the tournament and was not on the PGA Tour-provided charter flight, tested negative upon arrival. He is the first PGA Tour member to test positive for coronavirus.
"A total of 369 individuals (players, caddies, essential personnel) underwent on-site testing prior to the start of the tournament, with zero positive results."
The PGA Tour resumed at the Charles Schwab Challenge from last Thursday at Fort Worth, Texas, after a three-month hiatus because of the spread of coronavirus.
According to the tour's health and safety guidelines, Watney must self-isolate for 10 days but it is unknown whether he has to remain in South Carolina for the duration.
Watney, a five-time winner on the PGA Tour, shot 74 in his first round on Thursday, playing alongside compatriots Vaughn Taylor and Luke List.