A day after saying his back was "doing well" American star Fred Couples pulled out of the Barclays Scottish Open before the start at Loch Lomond today.

The 46-year-old, on his first-ever trip to the course, was a late withdrawal from the eve-of-tournament pro-am and then informed the organisers this morning that he was not fit enough to play.

His place went to qualifying school graduate Gary Clark, the Londoner finding himself himself paired with world number four Retief Goosen and Ian Poulter.

The key thing now for Couples, who has a history of back trouble, is to regain fitness in time for next week's Open championship at Hoylake.

That event is crucial to his hopes of regaining a Ryder Cup place after an absence of nine years.

The former Masters champion and ex-world number one lies 12th in the United States points race, which ends at next month's US PGA championship in Chicago.

Couples was joint third in the Open at St Andrews last year and in contention for much of Masters week at Augusta this April.

He did not play the Open in 2002 and 2004 because of back problems, but was healthy enough to earn a spot on the American Presidents Cup side last season - he had not played in that since 1998 - and had a crucial win over Vijay Singh in the last day singles.

He is hoping his experience could earn him a wild card from Tom Lehman if he fails to climb into the top 10, especially with five uncapped players currently occupying positions six to 10 in the United States standings.