on 5 august 2010 it was announced that mooney would be joining league one side colchester united on loan until 3 january 2011. he came on as a substitute in the u's first league game of the season, a 2–2 draw at exeter city. mooney then scored twice on his full debut for the club, with a pair of first half goals in a 3–0 league cup win over hereford united. he scored his first league goal for colchester in a 1–1 draw at home to carlisle united on 27 august.