Michael Keaton is of Scottish heritage, and his real name is Michael Douglas.
While making the film, Robert Duvall became very good friends with legendary ex-Celtic player Jimmy Johnstone. As a result, Duvall named his dog "Jinky", which was Johnstone's famous nickname, due to his abilities on the field.
Didier Agathe played for the "bad" team Rangers F.C. in the film. In real-life he played for their rivals, Celtic F.C.
Ally McCoist is depicted as an ex-Celtic player in the film, but in reality, he played for their fierce rivals, the Rangers.
Robert Duvall spent time with then Raith Rovers boss John McVeigh, and said his hard man attitude made famous Chicago Bears coach Mike Ditka look like a lamb.