Tiger Woods [Images] is expected to be sidelined for between four and six weeks after having arthroscopic surgery on his left knee in Park City, Utah on Tuesday.

The world number one and 13-times major winner, runner-up behind South African Trevor Immelman at the U.S. Masters on Sunday, has had two previous operations on the same knee.

His rehabilitation time will prevent his title defence at the May 1-4 Wachovia Championship, and probably also his scheduled appearance at the prestigious Players Championship the following week.

"I made the decision to deal with the pain and schedule the surgery for after the Masters," Woods said on his official Web site (www.tigerwoods.com).

"The upside is that I have been through this process before and know how to handle it. I look forward to working through the rehabilitation process and getting back to action as quickly as I can."

Woods initially had surgery on his left knee in 1994, to remove a benign tumour, followed by arthroscopic surgery in December 2002.

"Tiger has been experiencing pain in his knee since the middle of last year," Woods's manager Mark Steinberg said.

"When he had it looked at by his doctors, arthroscopic surgery was recommended. Tiger has played through the pain in the past but knew it would be better for him to have the procedure done as early as possible."

"Of course, we're disappointed when Tiger is unable to compete in a PGA Tour event," PGA Tour commissioner Tim Finchem said in a statement. "He's the No. 1 player in the world and a fan favourite wherever he goes.

"There is really never a good time for an athlete -- especially one of Tiger's calibre -- to take weeks off from competition during the season, but his health concerns have to come first."

The next major for Woods is the June 12-15 US Open at Torrey Pines outside San Diego, one of his favourite courses where he has won a record six Buick Invitational titles.