After making a name for himself as an up-and-coming talent at youth level and as part of the FAIS International squad,[1] Leech began his senior footballing career after being snapped up by UCD in 2003 for a deferred scholarship while he was still at school.

[4][5] He further excelled his ever growing profile by scoring an extra-time winner for Drogheda United in the 2006 Setanta Sports Cup Final against Cork City at Tolka Park on 22 April 2006.

[6] He was shortly loaned to Bohemians in July 2006 until the end of the season as part of Tony Grant's permanent move in the opposite direction.

Leech signed for Shamrock Rovers on 3 July 2008;[12] he made his Hoops debut the following day as a substitute against Cobh Ramblers.

Leech made an impressive start to his Pats career scoring twice in his first four games before suffering a broken leg against Dundalk on 27 March 2009.