“Eventually, I’m going to have to start strengthening this leg again,” Tiger Woods says during a news conference to promote the AT&T National golf tournament. (TIM SHAFFER/REUTERS)

Tiger Woods’s preparation for next month’s U.S. Open will consist of time spent in a walking boot to relieve pressure on his ailing Achilles’ tendon. He will move about on crutches to preserve his balky left knee and further alleviate resulting stress on his back. He will, he hopes, begin strength training on his left leg by the end of next week, because the muscles in it have atrophied from a lack of use.

When he will hit another golf ball — in competition or practice — he does not know.

“Eventually, I’m going to have to start strengthening this leg again,” Woods said Tuesday at Aronimink Golf Club, site of July’s AT&T National. “That timetable will determine when I can start hitting balls again.”

The Open at Congressional Country Club in Bethesda begins three weeks from Thursday, and it is becoming clearer that if Woods — still the game’s most transcendent star, even as he hasn’t won a tournament in 18 months — is able to play, he will do so with very little preparation, if any at all. He could not rule out that this round of injuries, suffered April 9 with a single swing in the third round of the Masters, would prevent him from appearing at Congressional. Though he said “all my docs have said it should be ready to go by then,” there is “absolutely” a scenario in which he would skip the event.

“But I’m not going to say that I’m looking at it that way,” Woods said. “I’m certainly looking at it that, with the proper treatment and the proper rehab, that I’ll be ready, and that’s what I’m trying to do.”

Speaking Tuesday for the first time since he withdrew from the Players Championship on May 12, Woods said it’s “doubtful” he’ll play in next week’s Memorial tournament. That would leave him with nine competitive holes — the nine he played, in 42 strokes, before he withdrew at the Players — between the final round of the Masters and the first round of the Open.

That, though, is the small view. Woods, 35, has had four surgeries on his left knee — procedures that date back to his days as an amateur — and there are questions about whether the problems will hinder him for the rest of his career.

“Obviously, it’s not what it was when I was little,” Woods said. “I’m sure, down the road, it may be more difficult. Hopefully I’ll be in a cart by then on the senior tour. But between now and then, I should be pretty good.”

Some experts in sports medicine, however, believe there is greater concern. When Woods won the 2008 U.S. Open, the most recent of his 14 major titles, he did so not only on a knee in which the anterior cruciate ligament was ruptured, but on a double stress fracture in his left tibia — a broken leg. The ensuing surgery left him unable to swing a golf club for six months.

“In order to have those fractures, you have to hit one bone against the other bone with sufficient force to break the bone,” said Mark Adickes, a former Washington Redskin who is now an orthopedic surgeon and sports medicine specialist at the University of Texas’s medical school in Houston. “What do you think that does to the cartilage that sits between those bones? That cartilage is significantly damaged.

“There is a certainty that Tiger Woods has arthritis in that knee. The question is: How severe is that arthritis?”

Woods said Tuesday that his doctors hadn’t suggested more surgery this time around. Adickes said any procedure to replace cartilage — it does not regenerate on its own — would take perhaps a year or two of recovery time.

“My concern, as a golf fan,” Adickes said, “is that we’re at the point where we’re only going to see flashes of brilliance from Tiger Woods for the rest of his career.”

Even a flash of brilliance would be welcome at this point. He fell to No. 12 in the latest Official World Golf Ranking, his lowest point since before the 1997 Masters — his first major victory. He has played in only five 72-hole events this season. Normally, Woods would play a round or two at an Open venue weeks in advance as preparation. Tuesday, he said, “That’s the game plan, and hopefully the game plan will pan out.”

But as with everything right now, he could not be sure.

“A lot of that depends on the injury, how it behaves over time,” Woods said. “I’d much rather take it slow and see how I progress, take it on a week to week basis. . . .

“It’s hard to look at it beyond that. I’m trying to hopefully get ready for the Open, and anything beyond that, I don’t know.”