Before the 2016 Masters, sitting in a rented house in Augusta and telling tales over dinner, golf great Gary Player explained to the Daily Mail’s Derek Lawrenson how seven or eight years earlier he had reached out and pinched Rory McIlroy’s stomach fat, like an overbearing pageant mom, and told the kid to shape up. “Rory, look at that weight you’re carrying,” Player recalled telling the then-skinny-fat McIlroy. “You need to strengthen your core.” And to further his point, Player, the golf world’s version of Jack Palance–doing-one-armed-push-ups-at-the-Oscars, invited McIlroy to sock him in his septuagenarian gut. “It’s like punching a wall,” McIlroy marveled, according to Player. “You’re right, I do need to get fitter.”

McIlroy certainly took the advice to heart. In 2007, the year he turned pro as an 18-year-old, McIlroy was still a teenager sans muscle tone. In 2010, when he won his first PGA Tour event, his fluffy hair was still the bulkiest thing about him, and that year he teamed up with trainer Steve McGregor to make major changes to his routine. McIlroy went from struggling to balance on one leg or do a 30-second plank to working out five times a week for an hour and a half per day and broadcasting his gym gains on social media with the fervor of a CrossFitter.

By the start of the 2015 Masters, the 5-foot-9 McIlroy had won four major tournaments, and the sleeves on his extra-smedium golf shirts no longer hung limply. His body fat fell from 24 percent to 10 percent, he gained 20 pounds of muscle, Men’s Health magazine photographed him for its cover, and The New York Times Magazine deemed his stroke “the best swing in golf.”

McIlroy finished fourth at that year’s Masters, and was named the European Tour Golfer of the Year. Last season, he was the FedEx Cup champion, and he remains one of the sport’s default favorites in any event that he enters. But he has also missed the cut in three of his past five major tournaments, including this weekend, when he shot a 78 in the first round of the U.S. Open at Erin Hills. And for most of 2017, he has been dogged by a worrisome stress injury to his rib cage that originally manifested as pain in his back, the latest in a series of ailments — from a jammed wrist thanks to aspirational stubbornness to a shredded ankle thanks to extracurricular soccer — that is growing kind of long for a guy who is still in his 20s.

On the same night in 2016 that Player boasted to Lawrenson about fat-shaming McIlroy, he also had glowing things to say about the player’s potential. “I think he has the best swing in the game,” he proclaimed, “and that commitment to fitness will prolong his time as one of the best players around.” A year later, chatting again with the Daily Mail about McIlroy during the 2017 Masters week, Player offered more praise. But this time, after a year that included McIlroy’s decision to skip the Olympics, a tough-love appraisal from Jack Nicklaus, and no new major victories, Player’s words came across as a little more tempered.

“It would be my instinct that Rory will establish himself as no. 1,” he said. “But I don’t know what his passion is. I don’t know what his dreams are. If he has the passion, if he has the desire, if he is prepared to make the sacrifice. There are so many ifs.”

There’s a point in many athletes’ careers when injuries go from being the temporary excuse to becoming the permanent problem. Penny Hardaway’s knee injury in 1997 led to a parade of knee, foot, and back ailments that ended his career far too soon. Tony Romo was perpetually one hit away from another season-altering broken bone. (Even when he’s sitting in the broadcast booth this season, Cowboys fans will be instinctively holding their breath.) Kerry Wood was too beautiful for this ugly world. Tiger Woods went from a cold-blooded assassin to a thoroughly broken man. And those last two examples in particular may be cautionary tales when it comes to a player like McIlroy.

A pitcher’s delivery and a golfer’s swing have some parallels. Both routinely torque the body in a way that is thrilling to behold and painful to contemplate. Both are highly repetitive motions that have grown increasingly punishing, thanks to the faster-higher-stronger ethos of professional sports escalation. (It’s rare now to see high-velocity pitchers throw a complete game, in the same way that it’s gotten harder for a golfer to contend unless he can absolutely smoke the ball off the tee.) And both rely on a carefully calibrated dance between precision and abandon, between focus and freeing the mind, that’s a whole lot like life, man: being in control involves letting go.

In 2015, the colorful and at times controversial swing coach Butch Harmon, who worked with Tiger Woods from 1993 to 2004, made an astute observation about the deterioration of Woods’s game. “He looks like he plays ‘golf swing’ now and doesn’t play golf,” Harmon said. “What I’ve seen in Tiger the last few years is he’s more of a robot trying to create positions in the swing instead of trying to play golf.”

Woods’s tendency to overthink his swing was a bit of a chicken-and-egg situation: His originally aggressive motion, bolstered for a time by a workout regimen and a set of biceps previously unseen in the golf world, ultimately led to injuries, which led to him monkeying around with his swing, and there the cycle began to repeat itself for years. Comparisons between him and McIlroy ramped up in 2014, when McIlroy reported knee and back “tweaks” during the Memorial Tournament, though his back-to-back British Open and PGA Championship wins later that year quieted some of the injury concerns.

But in early 2015, on the same Irish radio program, Off the Ball, where Harmon evaluated Woods, he also expressed worry about McIlroy’s workouts. “The only caution I would give Rory,” he said, “is: I see a lot of pictures of him lifting a lot of very heavy weights, and I think, in a way, you can almost hurt yourself in the gym if you get too bulky.” (He went on to praise the tall, lean Dustin Johnson as being in “absolutely perfect physical shape to play golf.”) And he wouldn’t be the only one to raise this concern.

Last February, the Golf Channel’s Brandel Chamblee, a former player whose best finish in a major was tied for 18th place (his Wikipedia trumpets “shar[ing] a first-round lead at the Masters Tournament in 1999” as a career highlight) concern-trolled McIlroy’s muscle gains during a conference call with reporters, saying that he feared McIlroy was following Woods down a “destructive path.” Admitting that “thus far, there’s been no signs that it’s adversely affected his game,” Chamblee nevertheless fretted for McIlroy’s future. “I say it with a lot of trepidation,” he said, “because it’s a different era for sure, and I don’t know the full extent of what he’s doing, but when I see the things that he’s doing in the gym, I think of what happened to Tiger Woods.”

McIlroy’s response was illuminating, amusing, appropriately cocky, and kind of a self-own: He tweeted a video of himself grimacing as he squatted free weights. (He later had to respond to various Twitter gorillas who critiqued his workout, reminding them that “I’m 165 lbs. I’m a golfer not body builder.”) Player tweeted a vintage photo of himself with a flat-top, squatting a child in fitness solidarity. Several months later, in July, NBC analyst Johnny Miller characteristically joined the fray, suggesting that McIlroy “overdid the weight room,” conjuring up Tiger Woods, and explaining that “you just get carried away, wearing the tight shirts and showing off their sort of muscles.”

When McIlroy won the Deutsche Bank Championship last fall, he said in his press conference that while he respected the opinions of analysts when it came to his actual golf game, he was frustrated by their comments about his time in the gym. “That’s my pet peeve,” he said. “Someone that says to me, ‘You’re in the gym too much.’ The reason that I play at such a high level, and hopefully will continue to play at a high level for the next 10, 15 years, is because of the work I did in the gym.”

He does have a point. The form and physique that McIlroy sported early on in his career weren’t exactly sustainable either; his early swing relied too much on the use of his arms to generate club speed, and this led to back issues even in his pre-jacked years. (In 2010, before he began working with McGregor, he had to take time off for back pain.) By adding core strength, McIlroy unquestionably added stability, a good basis for long-term success.

And not all of his injuries have pointed to too much time in the weight room. The wrist and ankle injuries were more freakish than anything else, the results of an inconveniently placed tree root and a lads soccer game. His most recent setback, the hairline fracture in the posterior section of his rib cage, is a somewhat common golf injury stemming more from on-the-course overuse than in-the-gym overexertion. And despite being in a relative “slump” this season, he still entered last weekend’s U.S. Open with a no. 2 world ranking and followed up his rough first round with a second-round score of 71 that included four birdies in the final six holes.

Still, there are a few concerning elements to monitor. A story of McGregor having to reign in McIlroy from hitting the gym during the week of the 2014 British Open was delightful when McIlroy won that tournament, but it speaks to a workout obsession that has the potential for diminishing returns. Earlier this year, Henrik Stenson noted that the trend of “really go[ing] after it” on the tee box could put too much strain on the bodies of players like McIlroy and Jason Day. McIlroy turned 28 years old only last month, and has already dealt with a variety pack of medical problems. When Woods was that age, in comparison, his injury history was limited to a benign tumor that was removed from his knee back in college, and a 2002 procedure to remove and drain a cyst in the same knee. And while Woods was always attuned to his physical condition, it wasn’t until around 2007 when he began to bulk up in a quite noticeable way. (The cycle of injuries and swing changes and tabloid appearances would soon follow.)

McIlroy believes that he injured his rib while testing out new equipment, which isn’t in and of itself a bad thing. But it suggests that he’s vulnerable to the sort of tinkering that can cause a player to stop playing golf and start playing “golf swing.” After many years of playing with a consistent stroke overseen by his longtime coach Michael Bannon, McIlroy began implementing “drastic changes” to his swing last year. Asked at the 2016 French Open what he was specifically trying to fix, McIlroy half-joked, “Have you got 10 minutes?”

After McIlroy missed the U.S. Open cut last Friday, golf world raconteur Steve Elkington, who has become best known for a Twitter feed that appears to be written by a malfunctioning troll algorithm, accused McIlroy of being “bored” without having Woods around to chase. “Without Tiger the threshold is probably 4 majors with 100mill in bank,” Elkington wrote.

As he likes to do, McIlroy shot back, attaching a screen shot of the “Achievements and awards” section of his Wikipedia page. “More like 200mil,” he wrote. “Not bad for a ‘bored’ 28 year old… plenty more where that came from.” It was a decent dunk on Elkington, but it was also a teensy bit bleak. Most of McIlroy’s biggest achievements came in 2012 and 2014 — not that long ago, in the grand scheme of things, but growing more distant with each passing Sunday. The question is whether he will one day be defined by his injuries, or whether he’ll be best known for transcending them. As he prepares for a busy and ambitious summer schedule, there are still so many ifs.