By Mark Lamport-Stokes
(Reuters) - Tiger Woods' decision to rule himself out of contention for next month's Ryder Cup was a wise one given his struggles since undergoing back surgery in March, but it also raises fresh concerns over the former world number one's playing future.
Questions will undoubtedly be raised as to whether he decided to return to competition too soon after having a procedure to treat a pinched nerve in his lower back.
Though he says he has always recovered quickly from surgeries, he looked tournament rusty and a shadow of his former self in his last four PGA Tour appearances, twice missing the cut and once withdrawing midway through the final round.
At the age of 38, Woods is perhaps also paying the price of long hours spent on the range and in the gym, where he has always pushed himself punishingly hard.
The 14-times major winner has had four knee surgeries over the years, along with a string of other injuries, and undergone several swing changes in an attempt to limit the more severe effects of the golf swing on his body.
He famously won the most recent of his major titles in a playoff for the 2008 U.S. Open at Torrey Pines where he defied doctors' orders to compete after suffering a double stress fracture in his left shinbone two weeks before the tournament.
Yet former PGA Championship winner Paul Azinger believes Woods' problems this year are not purely physical, and that perhaps he has spent too much time on yet another overhaul of his swing.
"He has gone from the artist to the engineer," Azinger said during last week's PGA Championship while commentating as a television analyst for Golf Channel.
"It is difficult to watch a Vincent Van Gogh paint by numbers. We want to see Tiger come back and get all of this stuff out of his head.
"The golf swing takes a second and a half. What is running through his head in a second and a half that has caused him to lose face and path awareness?
"Something is happening in the strongest and greatest mind that golf has ever known that is different, and he has got to fix it. It is not just physical."
Woods missed the cut at last week's PGA Championship, only the fourth time he has done so as a professional in the majors, having pronounced himself fit to compete on the eve of the tournament.
He suffered a different back scare during the previous week's Bridgestone Invitational, but said that was resolved after his physiotherapist popped back his sacrum (a bone at the base of the spine), which had loosened after he landed awkwardly in a bunker.
However, a similar problem occurred before Woods teed off in the PGA Championship second round, forcing him to restrict his backswing and rely on timing, a combination that left him a distant 15 strokes off the lead by the time he finished.
Butch Harmon, who previously worked as a swing coach for Woods, said he should have quit in that second round.
"I was surprised he played the back nine. He looked really sore on the front nine; he looked like he was in a lot of pain," Harmon said during a Sky Sports telecast.
"I think Tiger wanted to show, 'I came here to play, I'm going to finish my round'. I hope he goes home and gets healthy."
Though Woods ruled himself out of contention for a wild-card spot on the U.S. Ryder Cup team, Azinger had previously said he would not have selected the former world number one had he been captain this year.
"I don't see how you can take an injured player who is not playing well who has a two-way miss," said Azinger, who skippered the Americans to their most recent Cup victory over Europe, in 2008.
"Those are the two biggest concerns – injured and a two-way miss. Tiger also has not been the formula for success either. With all due respect to one of the greatest players of all time, I would say you have to pass him up this year."
Woods plans to return to competitive golf for the Dec. 4-7 World Challenge tournament which he hosts, to be played this year in Orlando, Florida.
That gives him almost four months to get his back muscles rehabilitated and healed, on the advice of his doctors, and then ease his way back into practice.
Only time will tell if following doctor's orders to the letter will help Woods get back to the sort of form which has earned him 79 career victories on the PGA Tour.
He will celebrate his 39th birthday in late December, so perhaps has no more than five or six years left in his prime as a golfer.
(Editing by Peter Rutherford)