AKRON, Ohio (AP) -- Tiger Woods was stricken with more back pain Sunday and withdrew after eight holes at the Bridgestone Invitational. He struggled to even take off his golf shoes before being driven away to an uncertain future.
In his third tournament since returning from back surgery, this had the look of a serious setback.
Woods injured himself playing a shot from edge of a bunker on the par-5 second hole. With all weight on his right leg, he took an awkward slash at the ball, fell back toward the sand and landed with a thud, and kept jogging out of the bunker from sheer momentum of the steep drop.
"I just jarred it, and it's been spasming ever since," Woods told a PGA Tour official before leaving.
Woods kept playing, hitting a number of shockingly bad shots. He hit one into the water from the fairway on No. 3, coming up some 30 yards short of the flag. And on the par-3 fifth hole, his tee shot was 65 yards short of the hole. From a bunker left of the seventh green, he blasted out and back into the fairway and made double bogey.
He grimaced at impact when he hit a 315-yard drive into the left rough on No. 9. Woods slowly stooped over with his right hand on his leg, reached toward his back and slowly bent down to remove the tee from the ground. Moments later, he stepped into a cart and headed for the parking lot.
At his car, Woods could barely switch out of his golf shoes. His caddie, Joe La Cava, drove him away.
"It's just the whole lower back," Woods said. "I don't know what happened."
Masters champion Bubba Watson said he didn't see Woods hit the shot that hurt him on No. 2, though he could tell as the round went on that something wasn't right.
"He hit some shots that we're not used to seeing Tiger hit, even when he's coming back from an injury like this," Watson said. "So obviously, something was bothering him. ... Like I told him when I shook his hand, I said, `I'm praying for you. Hope everything turns out good. Hope to see you next week."'
With the pain he showed leaving the course -- and just four months removed from back surgery -- it would seem unlikely that Woods plays next week at Valhalla, where he won the PGA Championship in 2000.
Woods is scheduled to play the opening two rounds with Phil Mickelson and Padraig Harrington. Mickelson was on the 11th hole -- not far away from No. 9 -- when he noticed Woods leaving.
"It didn't look good. It looked like he was really in pain," Mickelson said. "I hope he's OK. I hope he's able to play next week. I hope it's a muscle and nothing serious because I'm really looking forward to playing with him. We rarely get paired together. If we do, it's been early Saturday.
"As much as I love playing with him, playing against him, trying to beat him, we all want him in the field. We all want him back. I just hope he's OK."
If Woods does not play in the PGA Championship, that would be the end of his season. He would have to win the PGA to be eligible for the FedEx Cup playoffs. In six starts on the PGA Tour this year, Woods finished all four rounds only twice.
Woods had back surgery March 31 to alleviate an impinged nerve, forcing him to miss the Masters for the first time and the U.S. Open. He returned after three months to Congressional -- three weeks ahead of his own schedule -- and reported no pain in missing the cut by four shots at the Quicken Loans National. He also reported no pain in four rounds at the British Open. He finished 69th, 23 shots out of the lead, his worst 72-hole result in a major.
Woods was 3-over par for his round -- and 18 shots off the lead -- when he withdrew at Firestone.
He did not say whether he would be able to play the PGA Championship next week -- "Just trying to get out of here," he told the tour official -- though this surely would make it difficult for Tom Watson to consider Woods as a captain's pick for the Ryder Cup.
The U.S. captain has said for the last few months that he wanted Woods on the team if he was healthy and playing well.
Woods was doing neither.
Even so, he had not suggested until the shot on the second hole that his back was bothering him.
"Hey, this is supposed to be my second tournament back, not my third," Woods said after Friday's round at Firestone. "Everything is going pretty good. I've gotten a little bit better, and the good news is I'm still getting stronger."
This was the second time this year Woods had to withdraw in the middle of the final round. At the Honda Classic in March, he stopped after 13 holes. Woods chose to play the next week at Doral, and his back problems showed up Sunday after an awkward stance for a shot out of the bunker.
Woods said it was his physical training over the years and his discipline in following doctors' orders following microdiscectomy surgery that allowed him to recover quickly. He has gone through four operations on his left knee over the last 20 years, and said the back injury was "way more debilitating than I thought."
"Most of the people I talked to who have had the procedure have no idea how I'm even back here playing," Woods said at the start of the week. "They just can't understand that. When you have great protocols and you do everything perfectly, everything fell into place. I was able to get back. But now it's just continuing, and I still need to get much strong than I am now, and I still need to get much more explosive than I am now. That's just time."