PALM BEACH GARDENS, Fla. (AP) -- The road to the Masters got off to a bumpy start Sunday for Tiger Woods when he withdrew from the Honda Classic with what he said was a lower back injury.
Woods was 5-over par for the final round - 12 shots behind Rory McIlroy at the time - when he shook hands with Luke Guthrie on the 13th green and told him he was done. It was the farthest point at PGA National, and the tournament sent a van to collect Woods and his family.
Police kept the media from the parking lot.
''He just came over and said, 'I can't go anymore. It was a pleasure playing with you,''' said Luke Guthrie, paired with Woods the last two days. ''I just said, 'Take it easy. Feel better.' Pretty uneventful.''
But the speculation over his future figures to be a big buzz leading to the Masters next month.
Woods said through spokesman Glenn Greenspan it was a lower back problem that had started Sunday morning as he was warming up. He was to defend his title next week in the Cadillac Championship.
''Too early to tell,'' Woods said in a statement about playing next week at Doral. ''I'll get treatment every day to try to calm it down. Just don't know yet. Wait until Thursday and see how it feels.''
Woods already has played a limited schedule this year - 10 complete rounds. He was to play twice more before the Masters on April 10-13.
Woods said the spasms were similar to what he felt last August at The Barclays, where he dropped to his knees after hitting one shot. Woods finished that tournament in a tie for second, one shot behind Adam Scott.
It was the second time in two years that Woods has walked off the course in the middle of the final round. He quit after 11 holes at Doral when he was well out of contention - and then won Bay Hill two weeks later for his first PGA Tour title since his return from the chaos in his personal life.
Guthrie said he could tell early on in the round that something was not right with Woods.
''He made a couple of uncharacteristic shots - the first on 3 kind of was the first one,'' Guthrie said. ''I didn't know if he wasn't feeling the greatest, and it kind of seemed like he might have been protecting - came up and out of it. I didn't think much of it until maybe 11. I noticed he was bending down gingerly.
''He didn't mention it to me,'' Guthrie said. ''Obviously, he wasn't playing the greatest. I wasn't playing the greatest. He was battling out there. It's not like he was throwing in the towel. He was still trying.''
Woods started the final round seven shots out of the lead and was out of the tournament quickly. He muffed a tough chip in the rough on No. 2, and then took double bogey on the easy par-5 third hole with a drive that found the water hazard left of the sixth green. He bogeyed the fourth from behind the green, and then put his tee shot into the water on No. 6 and had to scramble to save bogey.
Woods had said earlier this year in Dubai that he spent the majority of his offseason working on his physical strength, at the expense of neglecting his game. He opened the year by missing the 54-hole cut at Torrey Pines (where he is an eight-time winner), and then tying for 41st in the Dubai Desert Classic.
The Honda Classic was his first tournament in a month, and he didn't make it to the finish line.
''If you're hurting, you're hurting,'' Guthrie said. ''You don't need to risk injuring yourself even more. He's had his share of problems with injuries. There's no reason for him to chance it if he's really hurting.''
This was the fourth time Woods has withdrawn from a tournament since returning from the chaos in his personal life at the end of 2009. He withdrew from The Players Championship in consecutive years, once in the final round because of a bulging disk, and then after nine holes in 2011 with a leg injury. He left in the final round at Doral in 2012 because of tightness in his Achilles tendon.
Two years ago at Doral, Woods was driven in a cart to the parking lot, and NBC Sports showed footage of his Mercedes-Benz driving out of the Miami resort toward his home about an hour north in Jupiter. This time, police blocked the media from entering the players' parking lot. Woods was seen getting out of a white passenger van with his mother and other members of his group.
It was the second time the No. 1 player in the world walked out in the middle of the Honda Classic. A year ago, McIlroy quit after 26 holes because of what he said was a sore wisdom tooth. He later said the frustration of a poor start to the year got the best of him.
By withdrawing in the middle of the round, Woods is ineligible to win the Vardon Trophy for lowest scoring average for having an incomplete round. Woods has won the award a record nine times.