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The PGA Tour confirmed the world No 2 had withdrawn just before his third round got under way on Saturday.
McIlroy is understood to have experienced muscle spasms in his back that would not go away.
- 2027 Ryder Cup: When is it and who will be involved?
- Ryder Cup: Latest headlines, reports and highlights
- Got Sky? Watch the Ryder Cup on the Sky Sports app ?
- Not got Sky? Stream golf and more with no contract ?
"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.
Coverage from the Arnold Palmer Invitational continues on Saturday on Sky Sports Golf and Sky Sports Main Event. Stream the PGA Tour and more with no contract
(c) Sky Sports 2026: Rory McIlroy withdraws from Arnold Palmer Invitational ahead of third round due to back injury
England intra-squad series teams announced with eight uncapped players given shot to impress in Pretoria ahead of Women's Cricket World Cup
Winter Paralympics 2026: Russian athletes win first medals since being allowed to compete under their own flag