He started his career with Manchester United, joining on a youth contract when he was 16 years old. After spending two years at the club and becoming disillusioned with the lack of first-team opportunities, McCormack turned down the offer of an extension to his contract. He moved to Italy and joined Serie B side U.S. Triestina Calcio, becoming the first Irish player to move to Italy since Robbie Keane’s brief stint at Inter Milan. McCormack endured a frustrating time at the club, failing to make a first-team start during his two and a half years there. He returned to Ireland to sign for League of Ireland champions Shamrock Rovers at the beginning of the 2011 season, playing a huge part in their journey to the Europa League group stages.
McCormack signed for League of Ireland champions, St Patrick’s Athletic in November 2013. He scored his first goal for Pats on his debut in a 4–1 win over Shelbourne in a friendly at Pearse Park on 1 February 2014. After 58 appearances for Pats, McCormack was released by mutual consent on the 28th of July 2015 and was announced as a new signing for relegation fighting Derry City later that day.
He signed with Cork City on the 18th of November 2016.
Extra.ie FAI Cup
SSE Airtricity League
UEFA Champions League
UEFA Europa League
EA Sports Cup
Munster Senior Cup