Born in Belfast, McCann played in the Distillery youth system from 1995 until signing for the West Ham United Academy of Football in 1996, where he started his professional career. He made his debut on 19 May 2001 in a 2–1 away defeat to Middlesbrough. McCann also won 39 caps for Northern Ireland after making his senior debut against Malta in 2001, with the last of his 39 caps won in a 6–0 friendly defeat against the Netherlands in June 2012.