Behold, the unfinished legacy of Tiger Woods. We know there is so much more he wants to do.

We just don’t know yet if he can. We just don’t know yet if he will.

Somewhere out there, Woods, 35, fights the relentless battle of wear and tear and tries to escape the ever deepening bunker of age. There will come a day when he has no way out, no chance to get up and down.

“Father time is undefeated in this league,” Miami’s Dwyane Wade said recently about the NBA. But that goes for any sport, even golf. Father time always eagles No. 18.

But for now, a body tries to recover. A champion, having spent years now recuperating his knee or his swing or his image, vows his return. Better than ever. Maybe. A sport waits. So, too, do the sponsors, the networks, the public, all those with some investment, emotional or financial, in Tiger Inc.

All are wondering when, but they are also possibly starting to wonder if. And also, what happens if not.

Painfully premature speculation? Maybe, especially to Woods. “It’s certainly not the doomsday that some of the press members are writing,” he said at a tournament news conference last month about the troublesome left knee and Achilles. He mentioned the ordeal of the ACL reconstruction in 2008. “This one’s,” he said, ”a cakewalk compared to that one.”

But the more golden the treasure, the deeper the concern when something — anything — goes wrong. And Woods’ anythings are starting to accumulate. He had planned to be back in the U.S. Open, which starts next week at Congressional Country Club in Bethesda, Md., and now he’s not. This healing business can take awhile. Sometimes, forever.

“My first reaction was uh-oh,” former Ryder Cup captain and television analyst Paul Azinger said in a phone interview with USA TODAY. “He played on a broken leg and torn ACL and won the 2008 U.S. Open, so how bad must this be?

“It could be career threatening.”

Say whatttt?

We just don’t know.

It has happened to the most glorious of them. Sandy Koufax was unhittable but retired at 30, born too early for Tommy John surgery. Bo Jackson was an athlete with rare gifts, but a bum hip. Gale Sayers could not be cornered by any defense, until the day his body gave out. All done too soon.

Injuries and foul fate can suddenly halt any career, even one on four legs. Consider Barbaro. But none lost the stage Woods would lose.

Still Commands Attention

He is still the king of his universe, even in a walking boot. Even ranked No. 15. The magic might be a little older, and certainly suffers from lack of use, not to mention scars from scandal. It has been 2½ years since he won a tournament. But all he need do is electrify a Sunday at a major again. All he need do is win again. It’d be like yesterday, even if in so many ways, it wasn’t.

“There was a time when 97% of the fans pulled for Tiger and 3%, for various reasons, didn’t,” Azinger said. “But now it’s about 50-50. But either way, when he’s playing people tune in. They are either watching him to cheer him or watching him hoping he fails. He’s still by far the most compelling athlete in the world. And by leap years, he’s the most compelling golfer.”

His shadow still stands, without need of a crutch. The television ratings still get a bump when he is around the lead, except that hasn’t happened very often lately. Many of the casual fans who watch the sport must be assigned to Woods.

Golf still need only to look at its paychecks to understand his worth. The PGA Tour total purse was $70.7 million in 1996, the year before he started his haul of majors. This year, it will be $288 million.

Four sponsors left him over the mess he made of his marriage, but others stayed with him. His apologies satisfied them. What they want now, are victories.

“For any sponsor to get the value they hoped for when they signed Tiger, he’s got to have the platform of playing for these major championships and he’s got to contend on Sunday,” said Kevin Sullivan, former White House communications director and now head of his own firm. “There’s still plenty of time. But obviously if you’re a sponsor, you’re disappointed you’re going to miss out on the platform of the U.S. Open. It’s a setback.”

So time goes by, each day he is older, and the dry spell is longer. Once, we thought he would blow past Jack Nicklaus’ major title record of 18 like an Indianapolis 500 car past the start-finish line. He was at 14 in 2008. He is still there. We know he wants it. We’re just not sure anymore if he will get it.

The issue does not seem to be whether we will see Woods return, but what Woods it might be. Will there ever be again the spectacular phenomenon, pre-knee and pre-divorce? The story was so perfect then. He was young, nearly unbeatable, apparently invulnerable. Neither his judgment nor his body had yet failed him.

Injuries Pile Up

But every man has flaws, and surgery can only fix so many. He has had four on that left knee alone. And that’s a problem for a right-handed golfer, for the knee must accept the force of the swing.

“Tiger Woods is battling a chronic knee problem,” Ronald Grelsamer of New York’s Mount Sinai Hospital, an orthopedic surgeon who specializes in sports related knee injuries. “Unfortunately, based on his physical history, there is a good chance that it is more than just a mild ligament strain. I hope that I am wrong.”

The world wanted to see if he would ever fully mentally recovery from his personal lifecataclysm. The world never got the chance. Woods has had his hands too full trying to stay physically in one piece.

Azinger: “There are two kinds of strength. There is the kind that you can pick up the back of a Volkswagen, which is slow, bulky strength. There is elastic strength, which golfers have. And when you swing, you create energy and that puts a tremendous amount of strain on your hips, legs, back, shoulders and knees. On the downswing, you can’t slow down. If you do that, you mangle your golf swing.”

Jack Nicklaus, during his Memorial Tournament last month: “My swing never caused an injury for me. I think Tiger’s swing, and I think a lot of swings of today, are far more violent.”

So in a way, the game Woods loves and once owned, makes his road back all the more tougher. He still has the steel-mind quest for perfection and a iron will to win, but those precious metals are a load for the body to carry, and a little harder each season, now that he’s turned 35. Age is something that practice can’t fix.

Even the most priceless of art will go nowhere, if in the back of a truck with flat tires. “In golf, when you’re No. 1 and then you start to slide,” Fred Couples said at the Memorial, “and your mind keeps telling you, man, I remember a year ago I could do this, and then two years ago I did that; that’s the toughest thing to go through. There’s no other guy who can pick you up but yourself.”

Jack Lesyk, adjunct assistant professor of psychology at Cleveland State University, suggests that the circumstances can be particularly challenging for an athlete who has been at the top so long.

“I’m not sure what’s going inside his head … whether he truly believes given time he could get back there again,” said Lesyk, president-elect of the Association for Applied Sport Psychology. Though cautious not to speculate on Woods, an athlete with whom he has not worked, Lesyk added: “In his heart of hearts, though, one wonders.”

Friends, peers, the quick-trigger media — many voices are counseling patience. Consider: Woods is still on pace to catch Nicklaus, who didn’t get to 14 majors until he was 35.

“He needs to get that knee fixed,” Mark O’Meara said at The Players Championship. ”I know how much he loves the game and I know how badly he wants to be competing. And the game needs him.”

Technological Advances Could Help

“With today’s technology, we are able to use 3D imaging to pinpoint specific areas that aren’t effectively working and firing in sequence the way they should be. We can find out the golfer’s limitations,” said Randy Myers, who works with a dozen PGA Tour players, including Dustin Johnson, Lucas Glover, Davis Love III and Brandt Snedeker. ”Once you do that, then you can work around those injuries.

“If you have multiple injuries like Tiger has with the knee and the Achilles, you want to take a look at what is causing those issues. Is it movement in the swing? Is it something where the hips aren’t moving enough?”

Nicklaus wants a healthy Woods. ”I told Tiger when I was on the phone with him, which is the same thing I told him a thousand times, nobody ever wants records to be broken,” Nicklaus said of the conversation when Woods called to say he couldn’t make it to the Memorial. “That’s obvious. I don’t care who it is. ‘But I certainly don’t want you not to be healthy and not have the opportunity to play to break records.’ ”

The word that shouts from all this? Uncertainty. The unanswerable questions of a fork in the road.

Woods could come back revived and carry his legend to unimaginable new heights. The audience is a sucker for a comeback, especially by one so many never wanted to see go away.

Or …

He was once golf’s natural. We don’t know if those days are gone.

Will his legacy include the warning of the uncertainty of success? Regrets at records not broken, tournaments not won, a prime that passed in the MRI machine?

Or is there a happy and healthy ending to all this? The sport can find other champions to market — the NBA lived on without Michael Jordan— and the sponsors other voices. But they only get so many sure things. Golf would continue, but be a land with a mountain missing.

Those who care will cling to the hope of Tiger Woods for as long as possible.

And so will he.

Contributing: Steve DiMeglio; Michael McCarthy; Joe Fleming