Stephenson was born in Lytham St Annes, Lancashire, England, and he was a pupil at Arnold School in Blackpool.
[5] Stephenson started his career as a rugby union player, and represented England at schoolboy level.
[7] Stephenson played right-centre, in the 6–19 defeat by Widnes in the 1984 Challenge Cup Final at Wembley Stadium, London on Saturday 5 May 1984.
[8] Stephenson played right-centre, and scored 3-goals in the 14–8 victory over New Zealand at Central Park, Wigan on Sunday 6 October 1985,[9] played right-centre, and scored 7-goals in the 34–8 victory over Warrington in the 1985 Lancashire Cup Final at Knowsley Road, St. Helens on Sunday 13 October 1985,[10] played right-centre, and scored a goal in the 11–8 victory over Hull Kingston Rovers in the 1985–86 John Player Special Trophy Final at Elland Road, Leeds on Saturday 11 January 1986.
[14] Stephenson played right-centre, and scored 4-goals for all of Wigan's points in the 8–4 victory over Manly-Warringah Sea Eagles in the 1987 World Club Challenge at Central Park, Wigan on Wednesday 7 October 1987,[15] played right-centre, and scored a goal in the 28–16 victory over Warrington in the 1987 Lancashire Cup Final at Knowsley Road, St Helens on Sunday 11 October 1987.