Courtney played with Derby County F.C. as a schoolboy, before joining Birmingham City as a trainee. Courtney received Telford's Player of The Season in 2004/05, which drew attention from League clubs, with Burnley beating Wolverhampton Wanderers F.C. to his signature.
However, after finding first-team opportunities hard to come by, Duane was put on the transfer list in May 2006, after making just 8 appearances (7 from the subs bench).
He has since signed for Welsh Premier Champions The New Saints for the 2006/07 season.