Couples pulled out just before the opening round of a tournament that serves as a warmup for the British Open.
'I couldn't have even walked down the first fairway, let alone play,' Couples said 'Every time I get up I feel like I'm going to fall down. It's not very good.'
The 1992 Masters Champion is hoping to use the British Open to gain Ryder Cup points, attempting to make the U.S. team after a nine-year absence. He ranks 12th on the points list, with the top 10 gaining automatic team places for the Sept. 22-24 matches at the K Club.
Qualifying for the U.S. Ryder Cup team ends with the U.S. PGA Championship next month.