Former champion Louis Oosthuizen and Peter Hanson both withdrew during Thursday's first round of the British Open Championship at Muirfield.
Oosthuizen, the 2010 champion, pulled out after eight holes due to a hip injury. The South African had withdrawn in two of his last four starts
"I am tremendously disappointed to have had to withdraw from the Open after just eight holes," Oosthuizen said in a statement. "The same hip problem that forced me out of the U.S. Open last month after just one round returned at Muirfield and meant I could not continue.
"I had been having problems with my neck and had had two lots of intensive treatment on Wednesday night and Thursday morning. It's the Open and I was confident I could get through after hitting balls twice before my round, but the old problem returned and that was that. It's a great pity."
Hanson, who was questionable to even start the championship with a back injury, withdrew after five holes. The 35-year-old also withdrew from the Greenbrier Classic two weeks ago.
Since both players started their rounds, they will not be replaced in the field. Joost Luiten, who had been the first alternate, did not get a chance to make his third straight Open Championship appearance.