Jason Day has a cast on his left hand to immobilize his injured thumb and isn't expected to return to competition until The Players Championship in three weeks.
Day's agent, Bud Martin, says the cast was put on Wednesday as a precaution.
Day injured his thumb while winning the Match Play Championship in late February. He took six weeks off before playing at the Masters, where he barely made the cut.
Martin says the inflammation is deep and easily irritated by simple tasks. He's expected to wear the cast for two weeks.
Day withdrew this week from the RBC Heritage at Hilton Head Island, S.C.