Career
Born in Salford, Greater Manchester, Tierney signed for Manchester United as a trainee in July 1999 and as a professional 12 months later. He was loaned out to Crewe Alexandra (where he scored his first career goal against ), Colchester United, and Bradford City. He made his senior debut for Manchester United on 3 December 2003 against West Bromwich Albion in the League Cup.
He signed for Livingston on 16 June 2005 having been released by Manchester United, but failed to impress in his first season at the club and they were relegated from the Scottish Premier League.
He joined on 2 June 2006 on a free transfer. In July 2007, manager Simon Grayson allowed Tierney to join Stockport County in a six-month loan deal.
At Stockport he scored once against Macclesfield in the Football League Trophy. Tierney returned to in January 2008, and in May 2008, he was released by the club
In September 2008 he signed for Conference National club Altrincham.
However, he left the club after less than a month. Tierney has also represented the Republic of Ireland at under 21 level Club Individual.
