He defied doctor's orders when he played in the U.S. Open last June. And we all know the historic outcome there.
But we also know that Tiger Woods is no fool, and he is certainly not fooling around when it comes to his rehabilitation and return to competitive golf.
Since knee surgery to replace the torn anterior cruciate ligament in his left knee, Woods appears to have followed the instructions of doctors, therapists, trainers and anyone else who has an influence in regard to his comeback.
Woods stuck to his pledge to not rotate on the knee for six months. Although he dabbled with chipping, putting and hitting short irons, Woods said recently on his Web site that it wasn't until early January that he began to hit all the clubs in his bag, and even then said he was not "swinging as hard as I can."
If Woods appears to be taking his time getting back between the ropes, perhaps the cautionary tales of others provided the necessary incentive to be careful rather than courageous.
Among golfers, players such as Ernie Els, Brad Faxon and Len Mattiace have had similar knee problems, and all admitted they might have pushed to get back too quickly. So while Woods might be tempted to return sooner rather than later, there are several examples that suggest he's smart to take his time.
"I had very similar, or I guess exactly, the same surgery as him, and he's probably doing the right thing," said three-time major championship winner Els, who suffered a left knee injury in the summer of 2005. He ruptured the ACL while water-tubing on a family vacation, but actually came back to win the Dunhill Championship in December of that year in his native South Africa.
"Your left knee is very important in the golf swing, and I still felt it at least a year, a year and a half after the surgery," Els said. "So it's something that major, and it's been a bit of a climb since then. He can probably come back earlier, but knowing Tiger, he wants to be 100 percent ready."
Remember last April? Two days after the Masters, Woods had what was referred to as routine arthroscopic surgery on his left knee. Nobody outside his inner circle realized his ACL was nearly gone. The idea of the procedure was to get him through the rest of the year, with the reconstruction to take place after the 2008 season.
But in his zeal to prepare for the U.S. Open at Torrey Pines in June, Woods suffered two stress fractures in his left tibia. Doctors told him in late May he needed to take six weeks off, with three weeks on crutches. As we know, Woods played anyway, winning in a dramatic playoff over Rocco Mediate, before announcing he was done for the year.
The stress fractures would heal, but ACL surgery is serious stuff, as many athletes in many sports can attest.
Philip Rivers, the San Diego Chargers quarterback who a year ago injured his knee in a playoff victory over the Indianapolis Colts, told reporters, "I remember that first week, feeling like, 'This is bad.'"
Rivers had arthroscopic surgery to clear out damaged cartilage a day later, then played six days after that in the AFC Championship Game against the New England Patriots. Three days later, after the Chargers had lost to the Patriots, Rivers had surgery to replace his ACL, but five months after the operation he was participating in offseason workouts.
"The first week or two weeks was really miserable. Just hurting. I can't sleep. Just getting situated. It hurts to straighten it out. Is it ever going to feel good?" Rivers said.
Woods has reported similar pangs of discomfort, saying it was all he could do to get from the couch to the bathroom. "It's been absolutely something I'd never want to do again," Woods said.
For Rivers, his return was swift. He was back at practice last June, a month before training camp was to begin.
"It's amazing," Rivers said, around the time Woods was winning the U.S. Open in the same city. "There are some times when I don't realize that I ever had anything. Out here [at practice], you have a brace and you're a little more conscious of it. But just around the house and stuff, there are times when I can go hours and not even think about it."
Rivers is just one example of athletes returning from ACL surgery and having success. Miami Dolphins running back Ronnie Brown tore his ACL in October 2007 and returned this past season to rush for 916 yards and 10 touchdowns. Redskins linebacker Rocky McIntosh, who tore his ACL in December 2007, played in all 16 games this past season.
Former Oklahoma quarterback Jason White tore the ACL in both knees in consecutive seasons -- 2001 and '02 -- then came back to win the 2003 Heisman Trophy.
And then there's baseball player Milton Bradley. He tore his right ACL in September 2007 while being restrained by San Diego Padres manager Bud Black, who was trying to keep his player from arguing with an umpire. But after signing with the Texas Rangers the following year, Bradley led the American League with a .436 on-base percentage. He also hit .321 with career highs of 22 home runs and 77 RBIs. He signed a free-agent contract to play for the Chicago Cubs in 2009.
Perhaps the fact that athletes in contact sports can return in what seems like such a short period of time makes golfers feel as if it should be no problem for them, too -- especially since they don't have to worry about running fast or getting hit by an opponent.
And since golfers' livelihoods depend on playing -- no guaranteed contracts or injury settlements -- they might get a bit antsy.
Mattiace, who lost in a playoff at the 2003 Masters to Mike Weir, injured both of his knees, tearing both ACLs while skiing later that year. He had surgery and -- despite a period of seven weeks when he was unable to walk -- returned to the PGA Tour the following March. Mattiace's game, however, has been slow to return, as he has yet to finish among the top 125 money winners since.
"I've been 100 percent for the last two years," said Mattiace, 41, a two-time tour winner who failed to earn his PGA Tour card last fall at the PGA Tour Qualifying Tournament. "I'm working hard to regain my status. It's been a battle. I was actually playing four months after surgery. I played at Honda, Bay Hill and the Players Championship. I could barely walk at Honda; I made the cut at TPC, one of the best fields in golf.
"I look back and could barely walk and had no strength. But I wanted to play."
"I was stubborn," Els said. "I wanted to come back as soon as possible. I had a very good surgeon, and my rehab went great. It was very painful, but you know, I wanted to get back, and I set a date for me of Sun City [in South Africa], and that was definitely too early. The doctors down there saw my knee and that I was crazy to play, it was so swollen. My doctor told me I couldn't do any more damage to my knee, and that was what I wanted to do."
And then there's Faxon, 47, a 26-year PGA Tour veteran whose last of eight victories came at the 2005 Buick Championship on a torn right ACL. Faxon had surgery three weeks later, then rushed back to play the season-opening Mercedes-Benz Championship in January 2006.
But in 26 tournaments that year, he made just 13 cuts, and his knee problems persisted.
Also bothered by a foot injury that required surgery, Faxon finished outside the top 150 on the money list for the first time in his career in 2007, then went in for what he thought would be arthroscopic surgery on his right knee. Instead, another ACL procedure was performed, along with two bone grafts and cartilage removal.
"I've become an expert on ACL surgeries," Faxon quipped.
Faxon tried several times to return in 2008, but didn't play again until October, when he missed three cuts. He also didn't reach the weekend at the Sony Open in Hawaii this season and missed the cut at the Bob Hope Classic last week.
"Tiger is superhuman, so he can come back probably faster than most," Faxon said. "But I also think he's very cautious, too. He'll make sure he does the right thing. It's his left side, which is so important in the golf swing. I know everybody is guessing about what he's trying to do."
We can gather from what Woods has told us that he has used the time off to improve his cardiovascular and physical conditioning, while waiting to put the kind of twisting pressure on his knee that he's been advised to avoid.
"The strength has come back better than ever," Woods said at the Chevron World Challenge in December. "I'm stronger than I've ever been in my legs. The range of motion is good. The only difference is I've just got to watch that I don't overdo it so the leg doesn't swell. But I haven't had much swelling. I haven't had much pain. I had a lot of pain early on, but lately, no."
We can only guess if Tiger is striping his tee shots and covering the flags with his irons as he prepares to come back.
But if he needs any inspiration for a quick return to greatness, perhaps Rivers, the Chargers quarterback, can offer it.
Coming off ACL surgery, Rivers tied for the league lead in touchdown passes with 34 and had the NFL's highest passer rating at 105.5.
Not bad for someone who risks getting pummeled on every play.
Tiger, meanwhile, will worry about pummeling the golf ball -- and without pain.
Bob Harig covers golf for ESPN.com. He can be reached at BobHarig@gmail.com.