Tiger Woods ruled himself out of the Ryder Cup on Wednesday, saying he will not return to competition until December because he needs time to strengthen his ailing back.
The 14-time major champion missed the cut at last week's PGA Championship with back spasms, a week after he withdrew from the World Golf Championships event in Akron, Ohio, with similar trouble.
Even so, US Ryder Cup captain Tom Watson said Monday he would still consider making Woods a captain's pick for the team to face Europe in September -- if the former world number one was sure he was healthy.
"I have already spoken to Tom about the Ryder Cup, and while I greatly appreciate his thinking about me for a possible captain's pick, I took myself out of consideration," Woods, 38, wrote on his website.
"The US team and the Ryder Cup mean too much to me not to be able to give it my best."
Woods said he would return to competition at the World Challenge unofficial tournament he hosts, which will be held December 4-7 in Orlando, Florida.
"I've been told by my doctors and trainer that my back muscles need to be rehabilitated and healed," he said. "They've advised me not to play or practise now. I was fortunate that my recent back injury was not related to my surgery and was muscular only."
Woods, chasing the record 18 majors won by Jack Nicklaus, admitted last week at Valhalla that he was stubbornly trying to play through pain.
"It was sore," he said after missing the cut on Friday. "It went out on me on the range."
Nagged by various knee and leg troubles over the past few years, Woods stressed the latest injury is in a different location than that of a March 31 operation to ease a pinched nerve -- one that sidelined him for nearly four months.
Woods missed the Masters and US Open while recovering from the surgery and played his first event since the operation in late June, missing the cut at Congressional Country Club.
Last month, Woods finished joint 69th at the British Open, marking the worst 72-hole major finish of his pro career.
He didn't qualify for the US PGA Tour's FedEx Cup playoffs, which start next week with the Barclays tournament in New Jersey.
Nor did he have any chance to make the US Ryder Cup team on points.
The United States will be trying to recapture the trophy from Europe when they meet in the biennial trans-Atlantic tussle September 23-28 at Gleneagles in Scotland.
"I'll be cheering for the US team," Woods said. "I think we have an outstanding squad going into the matches."