Bryson DeChambeau, the 2020 US Open champion, withdrew from the PGA Championship on Wednesday due to a left hand injury.
The 28-year-old American, known for his long driving, underwent surgery for a broken bone at the base of his left hand after missing the cut at last month's Masters.
DeChambeau played a practice round, testing his wrist and blasting drives.
"It was a huge ask for myself," DeChambeau told The Golf Channel. "I want to be 100% when I come back not 70%. Very disappointed. I want to give it my best. It's unfortunate."
DeChambeau said his wrist felt week as he struggled to put his full strength behind blasts off the tee.
"It started to feel like it was getting depleted of energy and I couldn't put my full weight into it," he said.
DeChambeau predicted he would be ready in two weeks to play the US PGA Memorial, a tune-up event for the US Open.
"Memorial is when I believe I'll be back at full strength," he said.
His departure allowed US alternate Denny McCarthy into the field for Thursday's start of the major showdown at Southern Hills.
McCarthy joins countryman Max Homa and England's Tyrrell Hatton off the 10th tee Thursday at 07:49 (14:49 SA time) - just two groups ahead of the huge crowds set to watch Tiger Woods, Jordan Spieth and Rory McIlroy.