Woods shot a career-worst 82 to miss the cut in the Phoenix Open by 12 shots. He was playing poorly at Torrey Pines when he withdrew after 11 holes because of tightness in his back.
Woods said Wednesdayon his website that the injury is not related to the back surgery he had last spring. He said he is having physical therapy every day and feeling better.
"Right now, I need a lot of work on my game, and to still spend time with the people that are important to me," he said. "My play, and scores, are not acceptable for tournament golf. Like I've said, I enter a tournament to compete at the highest level, and when I think I'm ready, I'll be back."
Woods is not playing Pebble Beach or Riviera, and said he would practice next week at his home and at The Medalist in Florida "getting ready for the rest of the year.''
He said he wants to play the Honda Classic that starts Feb. 26. If Woods skips the Honda Classic, he won't be eligible for the WGC-Cadillac Championship at Doral the following week, which would mean three full weeks of working on his game.
Woods said he expects to be playing soon.
"I am committed to getting back to the pinnacle of my game,'' he said.
Woods withdrew from his last PGA Tour event on Feb. 5 at Torrey Pines, saying he never loosened up after a fog delay. He had missed the cut a week earlier at Phoenix, shooting an 82 in the second round -- his worst score as a professional on the PGA Tour.
"He got treatment immediately on Thursday after he withdrew [from Farmers Insurance Open] and then after he got home," Woods' agent, Mark Steinberg, told ESPN.com's Bob Harig after the statement's release. "It alleviated the discomfort quite a bit. They said it's not surgery-related, and that was a huge relief. I don't know what you call it, but they're saying it wasn't related to the surgery and he didn't even need to go see a doctor."
His world ranking -- 62nd -- is the lowest since he turned professional in 1996.
"Nowhere did we say it was a leave of absence," Steinberg said. "He's going to work on his game, and when his game is back to form ... his game was in bad shape when he made swing changes in the past. He needs to work on this away from a public setting. He needs to work on this on his own. ...
"He's not pleased with where his game is right now. He's going to work on every single facet."
Since winning the 2008 U.S. Open despite a left knee injury that eventually resulted in reconstructive surgery, Woods has had knee trouble (including withdrawing two years in a row from The Players Championship in 2010 and 2011), a left Achilles tendon injury that forced him to withdraw from a World Golf Championship event in March 2012, an elbow strain that forced him to miss several weeks in 2013, back spasms and surgery to repair a pinched nerve in his back in 2014 that forced him to miss the U.S. Open.
Woods, 39, has played in 11 tournaments worldwide in the past year. He withdrew from three, missed the 36-hole cut in three others and missed a secondary cut in a fourth. He's finished 72 holes in a tournament just four times, with a best finish of 18th (in an 18-man field in his own postseason event last year).
In 2009, Woods was involved in an incident outside of his Florida home, crashing his car, and later admitted to marital infidelity. In February 2010, he issued a televised apology for his actions. He returned to play at the 2010 Masters.
ESPN.com's Bob Harig and The Associated Press contributed to this report.
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