Having progressed through the Bohs-SKB U17s and Bohemians U19s, Jack made the breakthrough into the first team squad towards the end of the 2020 season, making his first appearance as a substitute at Dalymount Park against Finn Harps. He went on to feature in the last League game of the season as well as the FAI Cup quarter final. While playing for the U19s Jack scored in the narrow aggregate UEFA Youth League defeat to PAOK in 2019.