Oklahoma:Davis Love III withdrew on Tuesday from this week's Wyndham Championship because of kidney stones. It was the second time this year Love has had to pull out of a US PGA Tour event where he had a hand in designing the course.
Love helped with the redesign at Forest Oaks in 2004, and won the tournament in Greensboro, North Carolina last year.
"I'm extremely disappointed not to be able to defend here," Love said. "I was hoping that we could take care of this matter between tournaments, but my doctor has advised me to take care of it as quickly as possible."
He is scheduled to have the kidney stones removed on Thursday.
Love also withdrew from the Canadian Open after helping with the redesign of Angus Glen.
Love is No 43 in the latest World Golf rankings. His departure leaves Anders Hansen, the 40th-ranked golfer in the world, John Senden (No 47) and Carl Pettersson (No 48) as the only top 50 players in the field.
Bubba Watson, Shaun Micheel, JB Holmes, Jerry Kelly and Steve Flesch also withdrew from the tournament on Tuesday. Watson cited medical issues, tournament officials said.