Tiger Woods is in doubt for this week’s PGA Championship after he withdrew from the WGC-Bridgestone Championship during the final round because of back pain.

Tiger Woods hits out of the rough on the 2nd hole during the final round. PHOTO: Getty Images Tiger Woods hits out of the rough on the 2nd hole during the final round. PHOTO: Getty Images

Woods, playing in just his 10th competitive round since returning to the Tour after microdiscectomy surgery on his back in March, hurt his back when he tumbled back into a bunker after playing an awkward shot on the 2nd hole. He battled on for another six holes before withdrawing. He was four over par and 18 shots behind the leaders at the time.

"I just jarred it, and it's been spasming ever since," Woods said. “It's just the whole lower back."

By the time Woods arrived in the Firestone Country Club car park he was moving gingerly and was unable to bend down to tie his sneakers. He cautiously got in the passenger seat and was driven away by caddie Joe LaCava.

Woods grimaces as he hist through the ball. PHOTO: Getty Images Woods grimaces as he hits through the ball. PHOTO: Getty Images

Asked if he was a doubtful starter for the PGA Championship, Woods told pgatour.com, "I don't know. Just trying to get out of here." He had planned to arrive at Valhalla on Monday for a practice round.

Woods is now unlikely to qualify for the FedExCup Playoffs. He was 215th in the standings heading into Firestone, with only the top 125 following the Wyndham Championship, in two weeks, being eligible to play on.

The two-time FedExCup champion, failed to qualify for the Playoffs in 2011 when knee and Achilles injuries sidelined him for three months in the middle of the season.

Perhaps, more importantly, he is 69th in Ryder Cup points, and appears likely to miss the matches at Gleneagles in late September. He has been on

Tiger falls back into a bunker and the damage to his back is done. PHOTO: Getty Images Tiger falls back into a bunker and the damage to his back is done. PHOTO: Getty Images

every American team since turning pro with exception of the 2008 matches after he underwent season-ending knee surgery.

On the eve of the Bridgestone Invitational Woods confessed that his back injury had proven more debilitating than he first thought.

"There's no comparison between a knee and a back," the 38-year-old said. "The knee is so much easier to deal with and rehab from than coming back from a back. I've had Achilles injuries, obviously knee surgeries, but this thing is just way different.

"Most of the people I talked to who have had the procedure have no idea how I'm even back here playing."