Only six months ago, Rory McIlroy played the best final round I had seen in a Major championship to capture the US PGA by a record eight strokes at Kiawah Island. Now, only six weeks from the US Masters, his game is in crisis.
Amid all sorts of speculation, McIlroy's first priority must be to satisfy the PGA Tour as to why he quit the Honda Classic midway through his second round on Friday. Otherwise there could be serious disciplinary repercussions.
His action, prompted apparently by an angry wisdom tooth, was reminiscent of another hugely controversial withdrawal by a Co Down golfing prodigy, 22 years ago. In fact, the circumstances were remarkably similar when Ronan Rafferty quit the 1991 US Open at Hazeltine National. After an opening 79, Rafferty was heading for a missed cut when he walked off the course midway through his second round.
Prior to his departure, he had given playing partners Corey Pavin and Craig Parry no indication of his intentions. And when questioned by the media afterwards, Pavin famously replied: "No guys. I'm pleading the fifth [amendment] on this one."
As it happened, a furious European Tour fined Rafferty £5,000 for his damaging behaviour at a time when they were desperate to get players into the US Open. Later, the player told me: "The truth is I was very low at that time. It's not often that I don't want to go out and play, and that was one of the times when I didn't want to play."
McIlroy expressed similar sentiments before departing PGA National on Friday, as in "I'm just not in a good place, mentally". One of his playing partners was Open champion, Ernie Els, who, unlike Pavin, reacted critically when saying: "I'm a great fan of Rory's but this wasn't the right thing to do."
It will be recalled that Els had hailed McIlroy as a future world No 1 during the 2009 Accenture Match Play in Tucson.
A far more revealing response came from David Duval, who has had to endure a spectacular tumble from the heady heights of world No 1 and Open champion of 2001. "Bad days and bad scores are part of golf," he Tweeted about McIlroy. "Don't tee off if your ego can't take it."
As for problems with his much-vaunted swing, there was an interesting observation from Els' caddie, Ricci Roberts. "If you look at a video now and when he was playing at his best, you can see his head dipping by as much as a foot," he said.
Christy O'Connor Snr saw something different in recent television viewing. "In a golf swing, what I like to call rhythm is hugely important," he said. "And Rory has it. But there are times when he turns the clubhead over slightly at the top of the backswing. It's something only a professional would notice, but that's when he hits not great shots."
If we've learned anything about McIlroy's competitive make-up over the last few years, it is that he's not a grinder. When he feels well, he plays well and when he's out of sorts, his game suffers. And clearly, he has been out of sorts since the start of this year. In this context, much is being made of his equipment deal with Nike.
Only the player can know the extent to which the change of clubs has affected his game. All we can assume is that the new clubs feel different, whether that's actually the case or purely psychological.
A professional golfing observer with whom I've discussed this issue has an interesting theory. He claims that the only way a leading player can extract the maximum from his game is to pick and choose his own equipment.
In this way, he could have four or five different brands in his bag, from putter to driver to rescues, mid-irons and wedges.
No manufacturer, he believes, has a full range of clubs that's going to match a top player's needs. The result is that compromises are inevitable, in pursuit of serious financial gain.
It also seems clear that McIlroy has not been playing sufficient competitive golf, certainly this year. Hours on the practice ground are no substitute for the heat of battle.
The player's missed cut in Abu Dhabi on January 18 was put down to rustiness, yet he then proceeded to take a further four weeks off before returning to action in the Accenture on February 21.
As things stand, he is committed to play only this week's Cadillac Championship and the Houston Open three weeks later in preparation for the Masters. In the wake of events which have limited him to a total of only four-and-a-half competitive rounds since mid-January, it will come as no surprise if he adds another event to his pre-Masters schedule.
It's hard not to be moved by the player's current plight.
From the first time I saw him as a 13-year-old during the Darren Clarke Foundation weekend at Portmarnock, he has been a credit to his craft. As Padraig Harrington put it: "Every time you meet Rory, you walk away thinking he's an even nicer guy than you thought. He keeps exceeding your expectations. You're waiting for him to act like he's world No 1. You're waiting for him to change and he doesn't. Except maybe to become even better as a person."
Similar views were expressed by O'Connor. "I was 26 for God's sake, when I played in my first big tournament, which was the 1951 British Open (at Royal Portrush). Rory will have made millions by that age. I like him. But geez, we have to remind ourselves that he's just a kid, a baby in tournament golf. And as No 1, he has to carry an awful load while behaving like he's top of the world."
We can but wish him well on what has become a painful journey.