La Jolla, CA (SportsNetwork.com) - Tiger Woods withdrew from the Farmers Insurance Open after 11 holes on Thursday because of a back injury.

Woods, who had been grimacing throughout the round, pulled out of the tournament on the No. 3 green at Torrey Pines' North Course, which was his 12th hole.

His tee time was delayed because of fog, which returned later to further delay action with just the first couple of groups on the course.

Woods was in the midst of his warmup session when the second fog delay hit.

It was the third time in his last eight official PGA Tour starts that he withdrew because of an injury.

Woods was out of action for three months in 2014 after having back surgery.

"It's just my glutes are shutting off. Then they don't activate and then, hence, it goes into my lower back," Woods explained. "So I tried to activate my glutes as best I could, in between, but it just they never stayed activated."

Woods, who has won the tournament seven times, hit a poor chip shot to open his round with a bogey at No. 10. After a poor tee shot on No. 11, he came up well short with his second and missed the green with his third but chipped in to save par.

He blocked his tee shot well right at the 12th and chipped to about 10 feet, then two-putted for a bogey. It was on that tee shot that Woods first showed signs of the apparent injury.

Woods scrambled for par on the next three holes, then hit his second shot at the 16th about six feet from the hole and drained the birdie putt to get back to 1-over par.

He parred the next two holes, then had another wait on the first tee. Woods poured in a birdie try from over 20 feet at No. 1 to get back to even-par.

But he made a mess of the second hole. He blasted a chip over the green, came up short with his next chip and after reaching the green with his fourth shot, two-putted for double-bogey. He found the green with his tee ball at the par-3 third, but withdrew before hitting his putt.