Mansell was born in Gloucester and began his career as a trainee with Luton Town, turning professional with the Hatters in August 2000.

He was transferred to Torquay United, one of the sides to survive at Oxford's expense on the last day of the previous season, on 5 July 2006 for an undisclosed fee.

He was awarded the captaincy in 2010, after Nicky Wroe was dropped for inconsistency and subsequently moved to Shrewsbury Town on 31 January 2011.

He made an excellent start to the 2011–12 season, scoring on the opening day at Plainmoor to rescue a point against Burton Albion on 6 August 2011[4] before scoring again in a midweek League Cup tie against Southampton, netting Torquay's consolation in a 4–1 loss.

Mansell scored the winning penalty in a 5–3 shootout victory at Wembley Stadium on 17 May 2015 as Bristol Rovers returned to the Football League after a one-season absence.

[16] Source:[17] On 25 September 2021, Mansell was appointed interim manager of National League North club Gloucester City following the sacking of Paul Groves.