Miami, FL (SportsNetwork.com) - World No. 4 Jason Day withdrew from the WGC- Cadillac Championship before teeing off on Thursday due to a thumb injury.

Day, who won the WGC-Accenture Match Play Championship in February, said in a statement that the thumb has been bothering him since that victory.

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

Day had played this event in each of the last three years. His tie for 20th in 2012 was his best finish in those three appearances.

The Australian has made just three starts this year. He won the Match Play, shared second at the Farmers Insurance Open and failed to make the final round at Pebble Beach.

Day hopes to return in time for the Masters in five weeks. He has two top-3 finishes in the last three years at the season's first major.