Rory McIlroy walked off the 18th green at PGA National last year and shared a big hug with his father after winning the Honda Classic to reach No. 1 in the world for the first time.

His departure Friday was nothing like that.

Hands in his pockets, he waited short of the green to tell Ernie Els and Mark Wilson that they would have to finish the second round by themselves. McIlroy was 7-over par through eight holes, on his way to another short week, and it was time for him to leave.

He walked off the green and kept going, around the golf shops, out to the parking lot and into his car. And just like that, he was gone.

The reason behind his abrupt departure remained a subject of debate.

"There's not really much I can say, guys," McIlroy told three reporters who followed him out to their car. "I'm not in a good place mentally, you know?"

They asked three times if there was anything wrong physically, and he said there was not. When asked about his swing, the 23-year-old from Northern Ireland brushed off the question by saying, "Yeah, I really don't know what's going on."

But an hour later, he released a statement through his management company that he couldn't concentrate because of a sore wisdom tooth that needs to come out.

"I have been suffering with a sore wisdom tooth, which is due to come out in the near future," McIlroy said. "It began bothering me again last night, so I relieved it with Advil. It was very painful again this morning, and I was simply unable to concentrate. It was really bothering me and had begun to affect my playing partners."

This much can be said for Boy Wonder.

With the Masters just more than a month away, McIlroy has played only 80 holes this year. He missed the cut in the Abu Dhabi Golf Championship with rounds of 75-75. After a four-week break, he was eliminated in the first round of the Match Play Championship after a sloppy performance against Shane Lowry. And after opening with a 70 that gave no cause of alarm on Thursday, he was done eight holes later.

"His demeanor looks a little different," said Graeme McDowell, one of his best friends. "I felt like he was a little off with his golf swing on the range. There were a few moans and groans coming from the bay next to me. It's normally a display. It's normally a clinic. It's superlatives coming from the coach and the caddie. That's the sign of a guy who's lacking a little technique in his swing and a little belief in his game."

McIlroy is still scheduled to play next week at Doral, and he could have some explaining to do.

Bad play is one thing. The question was whether McIlroy showed bad manners by leaving early, and while one person truly understands the level of pain or discomfort, it was enough to raise questions by his peers.

"I'm a great fan of Rory's, but I don't think that was the right thing to do," Els said.

Told about McIlroy's statement about the sore wisdom tooth, Els softened his stance, not wanting to judge another player's pain.

"I didn't see anything, but if he had a toothache, that's what it is, you know?" Els said. "Hey, it's tough. If you ask him how he's feeling now, he's obviously feeling terrible for what's happened this morning."

"I didn't notice anything," Wilson said. "He wasn't playing the way the world No. 1 plays normally. Didn't hit the ball where he wanted to, and he's a true gentleman, though. He ... wasn't treating Ernie and myself in a different way. He was upset with his golf and I guess he had enough for the week."

McIlroy, coming off a year in which he won a second major with a record, already set himself up for scrutiny when he left Titleist to sign an equipment deal with Nike that was said to be worth upward of $20 million a year. Instead of taking a long winter break, he spent much of December trying to adjust to his new clubs. McIlroy said Tuesday it wasn't the clubs; his swing was out of sorts.

"I'm sure the guy has got a lot on his mind," McDowell said. "When you start trying to prove things to other people and you stop playing for yourself, it's a dangerous place to be. ... Any player would have did what he's done with regard to the equipment change. He's one of the most talented players I've ever seen. Once he starts believing in himself, he'll be back."

Nike introduced McIlroy with blaring music and a laser show in Abu Dhabi, but it's been all downhill from there.

"Even though my results haven't revealed it, I really felt like I was rounding a corner," McIlroy said in his statement. "This is one of my favorite tournaments of the year and I regret having to make the decision to withdraw, but it was one I had to make."

Tiger Woods understands better than anyone in golf what it's like to have every move judged, though for Woods it started not long after he turned pro in 1996.

"You've just got to ... think about it a little bit more before you say something or do something," Woods said. "It can get out of hand, especially when you get into social media and start tweeting and all those different things that can go wrong. Jokingly saying something doesn't always come off as saying that, even though the intent was different."

News travels fast these days, except to Luke Guthrie.

The PGA Tour rookie with a load talent is too young to worry about anything about his own golf, and he was thrilled with a 7-under 63 to take a one-shot lead over Michael Thompson going into the weekend. He didn't find out about McIlroy until he walked through the doors of a ball room for an interview.

Woods had his own concerns, too. He rallied from a double bogey on his back nine to scratch out another 70 and make the cut on the number. He went into the weekend nine shots out of the lead, still hopeful that he can post something low on Saturday and get back into the tournament.

Among those within three shots of the lead were Geoff Ogilvy, Lee Westwood, Charles Howell III, Sean O'Hair and Justin Rose — just about everyone, it seems, except McIlroy.