Martinez had been furious at referee Stuart Attwell for the dismissal of Gary Caldwell for a tackle on Carlos Tevez during Wigan's 3-0 defeat at Eastlands on 29 March.
Martinez fined over Caldwell outburst
WIGAN manager Roberto Martinez has been fined £2,250 by the Football Association and warned as to his future conduct after being found guilty of improper conduct following comments made after the match against Manchester City last season.