Couples has battled back problems in the past. He told tournament officials of his decision on Tuesday morning.
A 14-time winner on the PGA Tour, Couples is just 121st on this year's money list with one top-10 finish in 15 events. The 1992 Masters champion has fallen to 144th in the world rankings.
This was to be the Seattle native's first appearance in the western Canada event.
This week's tee times
Full coverage for the Air Canada Championship