Rory McIlroy has pulled out of the Arnold Palmer Invitational at Bay Hill due to a back injury.
The PGA Tour confirmed the world No 2 had withdrawn just before his third round got under way on Saturday.
"While warming up in the gym this morning, I felt a small twinge in my back. As I started hitting balls on the range before the round, it worsened and developed into muscle spasms in my lower back," McIlroy said in a statement to the PGA Tour.
"Unfortunately, I'm not able to continue and have to withdraw," he added. "I was excited to compete this weekend. I wish the Arnold Palmer Invitational a great finish and look forward to being back next year."
It is only the third time McIlroy has been forced to withdraw from a tournament.
He left the Nedbank Golf Challenge in 2009 with a flu virus and food poisoning, and withdrew from the Honda Classic in the middle of the second round in 2013, first citing a sore wisdom tooth and a week later apologizing by saying his head was not in the right place.
The back spasms are not thought be to serious enough to keep him out of The Players Championship next week, where McIlroy is the defending champion.
Even so, it the first significant issue he has experienced with his back since the Tour Championship in 2023, when he played through discomfort. A month later, he went 4-1 and led Europe to another Ryder Cup victory.
He is approaching a big stretch of consecutive tournaments that culminates with the defence of his Masters title between April 9-12.
After earlier weather delays during the day, play on Saturday finished with four players still to conclude their third round.
Daniel Berger, the current leader, will return to finish his third round on Sunday, as will Akshay Bhatia.
Berger, through 15 holes, headed the leaderboard at 13 under par. Bhatia, through 16 holes, was two shots behind him in second place as it stood.
Austrian Ryder Cup star Sepp Straka was among a group a further two shots back after a third-round 66, with England's Harry Hall seven strokes off the pace in ninth after a 68.
World No 1 Scottie Scheffler posted a level-par 72 and is 10 strokes off the pace.
Coverage from the Arnold Palmer Invitational continues on Sunday on Your Site Golf.
