Born in Leeds, West Riding of Yorkshire, Liddell started his league career at Barnsley, making his début as a substitute against Portsmouth in 1992.

After helping his team to Associate Members Cup success in 1999,[1] he went on to become Wigan Athletic's Player of the Year for the 1999–2000 season.

In the 2001–2002 campaign, Liddell finished as the club's leading scorer, an instrumental part of the team that would reach the play-offs for the second time in succession.

During the course of the season, he scored the club's 1,500th league goal and his first career hat-trick against Brighton, following this up with another in a 4–1 defeat of Cambridge United.

[7] Oldham terminated his contract on 7 April 2009, effectively ending his career with the club after a four-year stint in which he made 144 appearances.

[8] Liddell dropped into Non-League football at the age of 36 when he signed for Northern Premier League club Bradford Park Avenue in July 2009.

[11] In 2002, he played with the senior Scotland squad in a 'behind closed doors' warm-up match against Dundee United, but was never selected for a full international.