Graeme McDowell withdrew from the Travelers Championship on Wednesday morning after being informed that his caddie has tested positive for the coronavirus.
McDowell tested negative for COVID-19 on Monday and Wednesday, and he told Golfweek on Tuesday that he has been asymptomatic for the virus. His longtime caddie, Ken Comboy, began experiencing symptoms last week and tested positive on Tuesday.
"When I look at the last four to five days, I have experienced some fatigue and muscle soreness myself," McDowell said in a statement released by the PGA Tour on Wednesday. "I didn't think of it as COVID related, but rather just the effect of being back on the road, back practicing, back playing and just a little tired after having a few months off.
"But now that Kenny has tested positive - and we've spent a lot of time together the last 10 days - I have to take those symptoms more seriously. That is why I am withdrawing this week. I want to do the responsible thing."
McDowell said he is leaving Connecticut and will drive home to Orlando, Florida. David Hearn has replaced McDowell in the Travelers Championship.
"If there's any chance that I could have it, I am not keen on risking the possibility that I could pass it onto anyone else this week in Hartford," McDowell said. "I decided to drive back to Orlando today, versus flying and those risks as well.
"I'm just going to take the scenic route down the East Coast of the USA for 17 hours and increase my knowledge of U.S. geography a bit."
McDowell told Golfweek that he would decide whether he needed to quarantine away from family once he got back to Orlando.
He missed the cut at last week's PGA Tour event in South Carolina after attending a friend's funeral with Comboy on June 15.
"I'd been through a huge amount emotionally and mentally, and a couple of weeks back into it after a few months off you're going to be a little tired getting your golf legs back," McDowell told Golfweek. "But the alarm bells have started to ring now that Kenny has failed this test.
"We're a close-knit team. We roomed together last week. We spent six hours in a car. He's carrying the virus, so in some way I have to be carrying it, too."
Overall, five PGA Tour golfers have withdrew from events because of the virus. Cameron Champ also withdrew from the Travelers Championship on Tuesday after testing positive, and Brooks Koepka, Webb Simpson, Chase Koepka are also pulling out of the event as a precaution.
Nick Watney tested positive during last week's event in Hilton Head.