PITTSFORD, N.Y. – Right toe and knee injuries forced Paul Casey to withdraw from this week’s PGA Championship. He was replaced in the field by PGA Tour rookie Sam Stevens.

Casey said he’d been trying new golf shoes recently and aggravated existing toe and knee injuries. The Englishman had been given an invitation into the PGA Championship based on his previous performances in the event and his status as a European Ryder Cup player.

“I feel awful that I get an invitation and then can’t play,” Casey said via text. “I talked to [PGA of America CEO Seth Waugh] about it. He was great.”

Casey spent most of the day Tuesday getting treatment on his knee and toe and said he’s not sure if he’ll be able to play next week’s LIV Golf event in Washington, D.C.

Casey was one of 18 LIV players in the field at Oak Hill but his and Martin Kaymer’s withdrawal earlier this week dropped that number to 16.