The midfielder was dismissed moments after former Saints player Jeff Kenna scored what proved to be the winning goal for an alleged elbow on the Birmingham goalscorer leaving Kenna requiring stiches to a facial wound.
Referee Steve Bennett sent Prutton off for violent conduct and he will miss the games against Man Utd (a) on January 31st, Fulham (h) on February 7th and Arsenal (a) on February 10th.