Fred Couples withdrew from the Champion's Tour Boeing Classic on Friday because of back problems on the first hole.
Couples, from Seattle, has a long history of back issues and took three weeks off before the tournament.
After his drive on No. 1 at the TPC Snoqualmie Ridge, Couples lagged behind partners Mark O'Meara and John Cook and rubbed his lower back. When Couples reached his ball, he had a conversation with O'Meara and the two fist-pumped. O'Meara and Cook hit their second shots and walked ahead. Couples told his caddie to pick up his ball and the two waited for a cart to return to the clubhouse.
"I didn't feel very good warming up," Couples said. "I hit the tee shot at No. 1 and then my lower back really locked up when I walked down to my second shot.
"It was like a bomb went off in my lower back. For this to happen in Seattle, this is a rough one."
