 Turning down an initial bid of £175,000 he transferred to West Ham for a fee of £430,000 in 1979 making him the most expensive teenage footballer at the time.Stewart made his West Ham debut on 4 September 1979, playing as a defender, in a League Cup game against Barnsley.His first West Ham goal, a penalty, came on 29 September 1979 in a 2–1 home win against Burnley.