Rory McIlroy says he might not play again this season

CHARLOTTE — Rory McIlroy's 2017 PGA Tour season may be over.

The four-time major champion intimated after his third-round 73 that his health had become an increasing burden on his game.

"I'm looking forward to 2018," he said in response to a question about his injury.

Then after closing out his PGA Championship with a three-under 68 on Sunday at Quail Hollow Club, he shed more light on an injury to his left rhomboid muscle in his back that he says may keep him out for the remainder of the season.

"The next big thing is April and that's really what my focus will be on from now until then," McIlroy said. "I don't know what I'm going to do. You might not see me until next year. You might see me in a couple of weeks time."

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In many ways, injuries have come to define McIlroy's year.

McIlroy, 28, won in May last year at the Dubai Duty Free Irish Open before claiming titles twice in three starts at the Deutsche Bank Championship and Tour Championship in September. That helped him to the FedExCup, which he followed with a stellar performance at the Ryder Cup.

McIlroy, who entered the year the second-ranked golfer in the world, was sidelined until March after he suffered a hairline fracture to his rib at the South African Open in January.

“I can’t even run at the minute because if my feet hit the ground hard at all, the vibration in my rib cage sort of hurts,” McIlroy said at the time.

He returned with three top-10s in four starts in March and April, including a T-7 at the Masters, when he began experiencing pain in his back during The Players Championship in May. He made the cut but was seen wearing kinesiology tape across his back. An MRI on the Monday after the tournament revealed the back pain was a "low grade response" following his previous rib injury.

Coming into the final major of the year, McIlroy's injury problems seemed to be behind him.

Fresh off T-4 and T-5 finishes in his last two starts, and playing a course where he boasts the lowest scoring average in the field, he was the bookies' pre-tournament favorite at 7/1.

Rounds of 72 on Thursday and Friday, compounded with a 73 on Saturday, meant McIlroy was little more than an afterthought for most of the tournament. It wasn't until his  68 on Sunday that he revealed the extent of his injury.

"I have upped my practice coming because I wanted to feel like I was in a good place in my game," he said. "But it's a tough one because I go out there and play and shoot decent scores, but when I come off the course, I feel my left rhomboid going into spasm. Inside of my left arm goes numb."

McIlroy plans to fly back to Northern Ireland directly from the PGA Championship to meet with his fitness expert, Steve McGregor. They'll discuss options, McIlroy says, with playing the 2018 Masters pain-free his primary goal.

"It's a Catch 22 ... if I'm capable of playing, I feel like, why shouldn't you? But then at the same time, if you are not capable of playing at your best, why should you play?" he said.

"I wanted to play the season, but I just haven't it allowed it the time to fully heal," he added. "But I know if I want to challenge on a more consistent basis, I need to get 100% healthy."