World number four Jason Day has been forced to withdraw from the WGC-Cadillac Championship at Doral in Florida with a thumb injury.

The 26-year-old has revealed that following a scan on the injury, he was advised to walk away from the contest ahead of his first-round tee time.

"My left thumb was bothering me at the Accenture Match Play Championship and the pain continued here this week," Day said in a statement. "I had an MRI yesterday here in Miami with Dr Lee Kaplan.

"Fortunately, the MRI was negative, but the doctor prescribed rest if I was unable to play today. My plan is to rest for a couple of weeks. I'm sorry to miss the Cadillac Championship, it looks like it's going to be a great event."

Meanwhile, Tiger Woods is fit to defend his title following a back problem.