He will follow his doctor's advice and sit out the remainder of the 2005 campaign. That means Els will miss the season's final major championship, the PGA Championship at Baltusrol Golf Club in two weeks, as well as the Presidents Cup.
'I injured my knee while on a sailing holiday in the Mediterranean and had to have surgery on it,' Els said on his website. 'As a result, I'm going to have to take a break from golf on the recommendation of my medical advisers.
'Basically it's the only sensible course of action, so that I can be sure of the promptest recovery period. Obviously the timing is unfortunate. Although let's face it, there's no such thing as a good time to get injured.'
Els has three worldwide wins this season, all coming on the European Tour. He has five top-10 finishes in 11 starts on the PGA Tour.
Els finished 47th at the Masters Tournament, tied for 15th at the U.S. Open, and tied for 34th in his last start at the Open Championship.
He was next scheduled to compete in next week's International.