Tiger Woods says he does not expect to pick up a club again until next year.

The world number one underwent knee reconstruction surgery earlier in the summer having defied medical advice to win the US Open.

The injury has ruled him out for the rest of the season including next month's Ryder Cup at Valhalla.

And it could be some time yet before he is ready to return to action.

"As far as swinging a club, that's not going to happen until next year," Woods said in his monthly newsletter. "I just don't have a choice.

"We simply don't know what type of swelling there would be or if there would be any residual effects the next day once you start wheeling and dealing on the knee. Everyone's body reacts differently. I could putt right now but I'm not going to do it."

Woods initially suffered the injury during last year's Open at Carnoustie and had two lengthy spells on the sidelines before returning to win his 14th major title at the US Open.

The 32-year-old says his rehabilitation is going well but admits there is no timetable regarding a possible comeback.

"I don't know what the doctors are going to tell me about playing golf down the road," he said. "I'm taking it day-to-day, week-to-week. All I'm doing every day is looking forward to my next day.

"I'm a lot more mobile, which is really nice," he added. "The big thing is I've started my rehab and can ride the (exercise) bike. I can't ride it hard - just motion - but am getting in two or three sessions a day.

"Initially, I probably lost about 10 pounds because I wasn't working out. All of that was muscle. I've put about two pounds back on, but I'm still pretty light. I'm eating mostly raw and organic foods that provide the most nutrients."