Rory McIlroy will know in the coming days if the back twinge that forced him to withdraw from the Arnold Palmer Invitational will jeopardise his defence of The Players this week or the Masters at Augusta National next month.
The world number two withdrew from a PGA Tour event for the first time since 2013 when getting ready for the third round at Bay Hill on Saturday.
The injury did not appear to be serious, but rather than take a chance, McIlroy opted to head home for treatment.
“While warming up in the gym this morning, I felt a small twinge in my back,” he said in a statement.
“As I started hitting balls on the range before the round, it worsened and developed into muscle spasms in my lower back.
“Unfortunately, I’m not able to continue and have to withdraw.”
McIlroy’s manager, Sean O’Flaherty, said: “He’ll get treatment over the coming days and will know more then.”
The Co Down man has worked assiduously on his fitness and core strength for more than 15 years, after getting a wake-up call when he was 20.
“It got really bad at the start of 2010,” McIlroy said of the back problems that plagued him in his youth.
“I played in the Masters and missed the cut. The back really wasn’t feeling good. The doctor said to me, ‘Look, if you don’t start taking care of yourself or getting stronger, you can seriously jeopardise how long your career is’. That was a wake-up call for me.”
“You’ve got a guy that sees thousands of backs a year, and he’s telling you that if you don’t start looking after yourself, the career that you thought was going to last 30 years might only last 10.
“That’s a pretty scary proposition.”
McIlroy (36) works on his fitness with performance coach Ro Sharma, who was with him on the range at Bay Hill when he decided to pull out.