Padraig Harrington is out of next week's BMW PGA Championship at Wentworth because of a knee injury.
The former Open and USPGA champion said on his website: "I originally picked up a knee injury during the Wells Fargo Championship, which then got worse during last week's Players Championship.
"After returning home I continued to have physio on what was originally a hamstring tear, which caused the popliteus muscle to become inflamed.
"This resulted in the inability to stabilise my knee, causing acute pain. As it hasn't improved significantly and the recommended course of action is a couple of weeks rest, reluctantly, I am forced to withdraw from next week's BMW PGA Championship."