The Travelers Championship has been hit by another coronavirus case after Denny McCarthy tested positive.
McCarthy, who shot an opening 67, is the fourth person to test positive at the event, following fellow player Cameron Champ and caddies Ken Comboy and Ricky Elliott.
The American revealed he had felt symptoms after Thursday's round and one of his playing partners, Bud Cauley, has also withdrawn as a precaution despite testing negative.
Matt Wallace, who also played alongside McCarthy, and all three players' caddies returned negative tests.
"I was feeling pretty tired and sore after the round yesterday but didn't think much of it because I had practiced a lot Monday to Wednesday," said McCarthy on Friday.
"Last night, I woke up in the middle of the night with additional aches and soreness and sensed something was off.
"I felt like the only thing to do was get tested at that point before I went to the course."
Cauley explained his decision to pull out was down to "an abundance of caution". He had carded a 69 on Thursday.
"I'm very thankful I have tested negative but have decided to withdraw out of an abundance of caution for my peers and everyone involved with the tournament," said Cauley.
Nick Watney was the first PGA Tour member found to have coronavirus since action resumed, the American testing positive at last week's RBC Heritage.