ORLANDO, Fla. -- Defending champion Francesco Molinari withdrew from the Arnold Palmer Invitational on Thursday because of a back injury.

Molinari shot 64 in the final round last year at Bay Hill for a 2-shot victory, his eighth title worldwide. He reached the semifinals of the Match Play a few weeks later, and then had a 2-shot lead with seven holes to play in the Masters when he twice hit into the water and Tiger Woods rallied to win.

The Italian has not won since Bay Hill, and he has said on more than one occasion that the Masters took a lot out of him.

Molinari was schedule to play Thursday morning with Rory McIlroy and Justin Rose. He was replaced in the 120-man field by Kyoung-Hoon Lee.