Citing back problems, Fred Couples has withdrawn from the Senior PGA Championship at Valhalla.
Couples, winner of the 1992 Masters, was replaced by Blaine McCallister.
Earlier on Monday, Tom Wargo also dropped out because of a bad back and was replaced by John Harris. Wargo is the last PGA club pro to win the Senior PGA.
Steve Pate, who turns 50 on Thursday, the first day of competition, will be making his senior debut at the tournament.