Louis Oosthuizen has been ruled out of the upcoming US PGA Championship due to injury.
The South African, who won The Open in 2010, withdrew during his first round at Muirfield this month because of long-standing neck, back and hip injuries.
And he is set to be on the sidelines for another two months as he undergoes "a period of rest, rehabilitation and strengthening", meaning he will miss the WGC Bridgestone Invitational in Ohio this week and the US PGA at Oak Hill the week after.
The 30-year-old added in a statement: "It is obviously very disappointing to miss out on playing in such prestigious tournaments.
"But these are injuries that I have been managing for most of the season. It is important that I now give myself the proper time to recover."
Oosthuizen is hoping to be fit in time to play the Alfred Dunhill Links Championship at St Andrews in late September, a week before the Presidents Cup at Muirfield Village in Ohio.
International team captain Nick Price admitted that Oosthuizen's health is a "concern" ahead of the biennial clash with the United States, and he hopes a period of rest will cure the problem.
"We really won't know if he's match-fit or not until the week before, and being one of the top four or five players that I have on the team, it's a concern," said Price.
"I said to him, 'just get healthy first.' That's the most important thing. I don't really want him to injure himself further. He has a hip flexor problem, and anything in the torso in the golf swing can be very painful.
"But we'll cross that bridge when we get to it. He's going to keep me posted on his progress, and he's gone back to South Africa to rest up."