Golf: Woods recovering after knee operation

World No 1 Tiger Woods has undergone knee surgery that could keep him out of the season-opening Mercedes Championship on next year's US PGA Tour.

Woods underwent a successful one-hour procedure to remove fluid inside and outside the anterior cruciate ligament, according to his official website.

Benign cysts also were removed in the surgery.

"I had been playing in pain for most of the year and felt it was time to take care of it," Woods said.

He will be off his feet for the next week before beginning light rehabilitation programme.

The injury means he could miss the Mercedes Championships in Maui, Hawaii from January 9-12.