In October 1956 he moved to Mansfield Town without having played a game for the Hoops.[4] He moved to Portsmouth in February 1958. He re-joined Mansfield Town in December 1961.[5] Having last played professionally in 1963, Chapman was banned from football following a bribes scandal two years later.[6]
The ban signalled the end of Chapman's playing career, although he played a few games for South African club East Rand United. (The ban was ignored by the Apartheid-era South African federation which had been suspended by FIFA.) He eventually returned to the game as a coach with Portsmouth and then Crewe Alexandra. He then served Wolverhampton Wanderers as chief scout, becoming interim manager following the dismissal of Tommy Docherty on 4 July 1985 after a second successive relegation saw Wolves fall into the Third Division. He remained in charge of the first team until Bill McGarry (previously manager of Wolves from 1968 to 1976) returned to manage the club on 4 September 1985.[7] However, McGarry's return as manager lasted just 61 days and he quit on 4 November and Chapman was restored to the manager's seat. However, he was unable to prevent Wolves from suffering a third successive relegation which dragged them into the Fourth Division for the first time in their history. He left on 15 August 1986, just before the start of the 1986-87 season.[8]
Chapman was a member of Northern Ireland's 1958 FIFA World Cup squad (though not one of the 17 players that travelled).