Comerford was added to the Kilkenny under-21 team in advance of the 1993 Leinster Championship. On 31 July 1993, he won a Leinster Championship medal after scoring two points from right wing-forward in the 4-13 to 2-07 defeat of Wexford in the final. Comerford retained his position at right wing-forward for the All-Ireland final on 12 September 1993. He was held scoreless in the 2-14 to 3-11 draw. Comerford was switched to midfield for the replay on 3 October 1993, however, he ended the game on the losing side after a 2-09 to 3-03 defeat.