DiarioSport says Capello was never fully convinced by Casillas and rated his understudy, Diego Lopez, ahead of the Spain international.
After the defeat by Racing Santander, Capello wanted to dump Casillas to the bench, but was warned against the move by the Real board. The directors insisted Casillas was untouchable.
In the end, Capello chose to stick with Casillas and was rewarded with the championship. Lopez, meanwhile, has since been sold to Villarreal for a healthy £4 million.