Grant Elgin began playing soccer at a young age and played for several youth academies in his home state of New Jersey before finishing his youth career with Players Development Academy (PDA). He attended Northeastern University and played for their Division 1 men's soccer program. In his final year he was named captain while starting and playing in every game for the Huskies, logging a team-high 1670 minutes. Between his collegiate seasons, Grant also played for various semi-professional teams that competed in the USL League Two: Long Island Rough Riders, Boston Bolts, and GPS Portland Phoenix.