Bryson DeChambeau's Open Championship preparations were dealt a blow on day one of the John Deere Classic as he was forced to withdraw midway through his round.
The defending champion had found some consistency after a mixed start in Illinois, sitting three under after 15 holes.
However, he was unable to continue as a shoulder problem picked up on the second hole brought a premature halt to his day.
DeChambeau now faces an anxious wait to see whether the injury will clear up in time for next week's Open at Carnoustie.
"On two, I hit the shot out of the rough on the right and I just didn't feel great after that," he said. "I was feeling great coming into today.
"It's really unfortunate, especially with how well I was hitting it coming into this week, I don't know. Life just throws you curveballs and you just got to work with them. It's not fun.
"I'm not in too bad of pain with my arms down. It's when my elbow gets above my shoulder that it really, really doesn't feel great.
"I'm not going to not make the trip to Scotland. I mean, I feel like-look, I can still swing and hit a shot. I just don't feel like it would be productive to do so. I don't feel like it's going to be too long a recovery time.
"I had the same kind of thing kind of happen to me at Valspar, and it was a pretty bad injury on my back. I was able to recover and obviously finish second at Arnold Palmer, so, you know, my body is pretty resilient.
"If I can get three or four days of good rest in, when I get there Monday night I'll evaluate it and see how I feel."
While DeChambeau's challenge ended earlier than expected, Steve Wheatcroft enjoyed a productive day as he shot a 62 to lead the field by one.
Wheatcroft reeled off six successive birdies to surge up the leaderboard and put him in with a chance of earning the Open spot that comes with victory.
Michael Kim is his nearest challenger on eight under, with four players a further shot back heading into the second round.
