Jim Furyk managed to play only six holes before withdrawing from the BMW Championship in Illinois with a wrist injury.
Furyk was one over par when he brought an early end to his tournament at Conway Farms, the same course on which he shot a magical round of 59 only two years ago.
The withdrawal casts doubt on Furyk being able to play in the Tour Championship in Atlanta next week as well as the Presidents Cup in South Korea from October 8.
"I'm very concerned," said Furyk. "I would like to be ready for both of them, and if I can't get ready for next week, I would like to get ready for the Presidents Cup.
"But also I want to play with a chance to compete, and right now being out here I have no chance to compete this week with the pain I was feeling and with what I had shot-wise."
Furyk said his wrist injury initially flared up during the Deutsche Bank Championship, the second FedEx Cup play-off event, before it worsened after Wednesday's pro-am competition at Conway Farms.
"I'm in pain out there and I'm not near 100 per cent," he added. "I don't know if flinching is the right word, but I'm having a hard time getting through the ball on the ground right now.
"On [hole] 15, I had that little half-wedge and it was pretty painful to hit the shot. It's just not worth being out there."
Furyk had not withdrawn from a PGA Tour event in 20 years, a span of 477 straight events.