To research his role, Charlie Hunnam met with real members of the ICF (the Inter City Firm, the name given to West Ham's former hardcore firm of football hooligans).
Charlie Hunnam wanted Tommy Flanagan, to play the role of his older brother, even going to a bar for three nights that he knew Flanangan frequented with a script in hand for him to read. They would later co-star on 'Sons of Anarchy'.
Creator of the critically acclaimed FX series Sons of Anarchy (2008) Kurt Sutter has claimed he had his eye on Charlie Hunnam for the lead role of Jax Teller after seeing this film.
West Ham were approached by the film-makers who wanted to shoot scenes at their Upton Park ground. As they were under the impression that the film was celebrating the glorious game and its fanatical supporters, they agreed. Once they realized the film's true take on the subject (after filming had taken place), they disassociated themselves from the project.
Cass Pennant: One of the Manchester riot police at the train station. Cass Pennant was one of West Ham United's Inter City Firm's (ICF) leaders and a notorious hooligan in the late '70s.