"It's sort of the way it has been the last few weeks", McIlroy said. It could be sometime next year.
"This sounds bad but I'm trying to get this week out of the way before I start to think about that".
"The next big thing is April and that's really what my focus will be on from now until then", McIlroy said.
McIlroy, 28, won in May a year ago at the Dubai Duty-Free Irish Open before claiming titles twice in three starts at the Deutsche Bank Championship and Tour Championship in September.
As the reigning FedEx Cup champion, McIlroy's schedule was believed to include the first playoff event, the Northern Trust, in two weeks, ostensibly followed by three more tournaments in the next four weeks. This year was all about injuries, and apparently he's not over them yet.
'As I'm talking to you I can feel my left rumboid (upper back muscle) going into spasm, and the inside of my left arm going numb, ' said the 28 year old. "It's sort of the way it has been the last few weeks". 'I have upped my practice coming into the last two events because I wanted to feel in a good place about my game.
"Right now I can feel my left rhomboid going into spasm". "If I'm capable of playing, I feel like why shouldn't you".
"I don't know what to do", McIlroy said. "If I want to challenge on a more consistent basis, I need to get 100 percent healthy".
McIlroy has headed home to Northern Ireland and planned to meet with his trainer to figure out the next step.
McIlroy, who was among the favourites to win at the Charlotte course, was never truly in contention at the year's final major. Johnson's top-30 placing was his best finish at a major since winning the US Open a year ago. "Got back and playing it felt OK through the Masters".
After admitting an injury has nagged him for weeks and he was uncertain about his future, McIlroy made it clear he will spend the next week sorting out his plans for the remainder of the year.
But he didn't have many answers when he left Quail Hollow. But it's still there. I feel like I'm capable of playing well and winning and putting rounds together.
"I can play 18 holes".
Asked "why" he would play in the FedExCup events, McIlroy's answer was rather damning.
"It felt okay through the Masters and I switched it off for a couple of weeks because I was getting married, going on honeymoon". If I was injury-free, that wouldn't happen.
The FedExCup Playoffs begin August 24 at THE NORTHERN TRUST, followed by the Dell Technologies Championship.
"I don't know what I'm going to do", McIlroy said Sunday following a 3-under-par 68 to conclude his PGA Championship. You might not see me until next year, you might see me in a couple of weeks' time.
Dustin Johnson has blamed a tumble down the stairs at the Masters in April for his "frustrating" major campaign which in no way lived up to his world No1 billing.
McIlroy began the week 43rd in the FedEx Cup rankings and needs to be in the top 30 to qualify for the season-ending Tour Championship in late September.
Jordan Spieth closed out his run at Woods' record with a 70 in the final round, leaving him 2 over for the tournament.
PGA Championships 2017 prize money: How much will players earn?
McIlroy hasn't won a major since the 2014 PGA and struggled again this week.