Miami - Tiger Woods pulled out of the fourth round of the Cadillac Championship at Doral on Sunday with tightness in his left Achilles tendon, a worrying setback less than a month before the Masters.
Former world number one Woods, who could be seen limping during the round, left the course after 11 holes, was taken by a golf cart straight to the players' parking lot and drove himself away long before England's Justin Rose collected the title.
"I felt tightness in my left Achilles warming up on Sunday morning, and it continued to get progressively worse," Woods said in a statement later.
"After hitting my tee shot at 12, I decided it was necessary to withdraw.
"In the past, I may have tried to continue to play, but this time, I decided to do what I thought was necessary."
Woods said he would seek medical advice early next week.
Webb Simpson, who played alongside Woods, said he didn't see anything amiss until Woods teed off on 12.
"I didn't really notice anything," Simpson said. "I wasn't paying much attention, but it looked like he made a swing on 12 that really hurt. But (he) didn't say a whole lot. Class act. Shook my hand. Off he went."
Simpson said Woods didn't say what the problem was, but that he "got upset" after his last tee shot of the day.
"He just said he's got to be done," Simpson said. "It looked like he was in some pain."
Woods, a 14-time major champion, hasn't won an official event on any tour since the Australian Masters on November 15, 2009.
Shortly after that he was embroiled in a sex scandal that eventually ended his marriage.
His return to top form since then has been hindered by injury, including left knee and Achilles tendon injuries that he suffered en route to a fourth-placed finish at last year's Masters.
They kept him out of last year's US and British Opens, but he seemed to be on the upswing with a victory in the unofficial Chevron World Challenge in December, and he carded an impressive 62 in the final round of the Honda Classic last week.
Woods had said his left knee, surgically repaired four times, has been as strong as it's been in years.
His most serious operation on the knee was reconstructive surgery in June 2008 to repair ligaments a week after he won the US Open at Torrey Pines.
That victory was his last major title.
Woods is scheduled to play in a fortnight at Bay Hill, which was to be his final tuneup for the Masters, the first major of the year at Augusta National from April 5-8.
The elite WGC event at Doral was Woods's third straight tournament, although he had a relatively short week at the WGC Match Play Championships with a second-round exit.
Asked after the third round here how his body was holding up, Woods answered "It feels great".
A hobbled Woods changed his shoes at the turn. His limp appeared to worsen after his second shot from the rough at the par-five 10th, which he bogeyed.
It marked the third time in three years that Woods has pulled out in the middle of a tournament, most recently at the Players Championship last May. After that he took a break of several months to let his left leg heal.