Woods said his suffered a mild sprain of the medial collateral ligament in his left knee and a mild sprain to the Achilles tendon in his leg left during third-round play at the Masters. He completed the tournament, however, finishing fourth.
Physicians told Woods to rest and also suggested cold-water therapy and soft tissue treatment. There is no timetable for Woods to return to tournament golf but he ruled himself out for the Wells Fargo, which is to be played May 5-8.
Woods had surgery to repair the anterior cruciate ligament in his left knee after his victory at the 2008 U.S. Open.
"I personally contacted tournament officials and expressed my regret in not being able to play," Woods said in a statement on his Web site. "This is an outstanding event but I must follow doctors' orders to get better."