Padraig Harrington has tested positive for Covid-19 and has withdrawn from the AT&T Pebble Beach Pro-Am.
The three-time Irish major winner was frustrated to miss the cut at the Phoenix Open last week, the first of three PGA Tour events he was to play in consecutive weeks before returning to Dublin.
But now Harrington, 49, faces a period of time in isolation after testing positive for coronavirus.
"Thanks very much for everyone’s well wishes," he tweeted. "At the moment I’ve just the symptoms of a cold.
"If it doesn’t get any worse I’ll take that as a piece of good luck.
A PGA Tour statement said: "PGA Tour member Padraig Harrington has withdrawn from the AT&T Pebble Beach Pro-Am after testing positive for Covid-19.
"Harrington will have the PGA TOUR's full support throughout his self-isolation period under CDC guidelines.
"First alternate Sangmoon Bae will replace Harrington in the field."
World number one Dustin Johnson, who won the Saudi Invitational event on the European Tour last weekend, has withdrawn from this week's Pebble Beach tournament.
The event is dropping the amateur element this year due to the pandemic and using two golf courses - Pebble Beach and Spyglass Hill - instead of the traditional three.
Harrington is set to captain the European team at the Ryder Cup, which has been rescheduled from last year to take place at Whistling Straits in September.
