SAN DIEGO — In an ominous start to his season, Tiger Woods walked off the course after 11 holes Thursday at the Farmers Insurance Open because of tightness in his lower back that he attributed to a fog delay.

Woods began reaching for his lower back midway through the round on the North Course at Torrey Pines, and his grimace became more pronounced. Billy Horschel picked up the tee for Woods on their 10th hole and took the ball out of the cup for him when Woods made birdie.

Woods hit a safe shot to the middle of the par-3 third green. When it was his turn, he had caddie Joe LaCava pick up his ball marker and he waited for Horschel and Rickie Fowler to finish before getting into a cart and driving to his car.

In his last six tourneys since returning from back surgery a week before the Masters, Woods has missed the cut three times, withdrawn twice and finished 69th in the British Open, his lowest 72-hole finish in a major.

He had said at his unofficial Hero World Challenge in December and last week in the Phoenix Open, where he had a career-high 82, that he was at full strength.

He blamed this on having to stand around in the cool Pacific air during a fog delay.

Woods warmed up for his 9:20 a.m. tee time and was near the 10th tee when play was suspended because fog rolled in. Fog delayed the start by an hour, and the next round of fog led to a 90-minute stoppage in play.

“I was ready to go,” Woods said. “I had a good warmup session the first time around. Then we stood out here and I got cold, and everything started deactivating again. And it’s frustrating that I just can’t stay activated. That’s just kind of the way it is.”

Asked if it was new pain from the back injury that forced him to withdraw at Firestone in August, Woods said his “glutes are shutting off.”

“Then they don’t activate and then, hence, it goes into my lower back,” he said, sounding more like a physical therapist than a 14-time major champion. “So I tried to activate my glutes as best I could in between, but they never stayed activated.”

Woods was 2-over par through 11 holes and in a tie for 130th when he withdrew.

He will fall to his worst world ranking since before he won his first PGA Tour event as a 20-year-old in 1996, and he most likely will not qualify for a World Golf Championship for only the second time in his career. Woods is not expected to play again until the Honda Classic in three weeks. Doral is the following week. He did not indicate earlier in the week that he would add tournaments to his schedule ahead of the Masters in April 9.

LPGA: Brooke Pancake shot a 6-under 67 to take a one-stroke lead in the suspended first round of the Bahamas LPGA Classic at Paradise Island.

Play was suspended for the day at 2:47 p.m. and more than inch of rain fell on Atlantis Resort’s Ocean Club course.

CHAMPIONS TOUR: Colin Montgomerie knows how to knock Bernhard Langer off the tour’s top spot.

“The goal is to redirect Langer to other sites, so we all have a chance of beating him,” Montgomerie said, smiling.

Won’t happen. The Allianz Championship, the tour’s first full-field event, starts Friday on The Old Course at Broken Sound Golf Club in Boca Raton, Florida. Langer lives 15 minutes from the course, and he has used the home cooking to finish in the top three in five of the last six years, including a victory in 2010.