Comerford first lined out for Kilkenny as a member of the minor team during the 1990 Leinster Championship. On 8 July 1990, he was listed amongst the substitutes when Kilkenny faced Laois in the Leinster final, however, he was introduced as a 36th-minute substitute for team captain James McDermott at midfield. Comerford scored three points and claimed a winners' medal following the 3-15 to 0-15 victory. On 2 September 1990, he lined out at centre-forward when Kilkenny qualified to play Cork in the All-Ireland final but was held scoreless in the 3-14 apiece draw. Comerford retained his place on the starting fifteen for the replay on 30 September 1990, however, he was switched to right wing-forward. He scored two points from play and claimed an All-Ireland medal after the 3-16 to 0-11 victory.