[1] He mainly played basketball as a junior and only converted to Australian rules football after missing selection in a state squad.
[2] Due to a series of shoulder and hamstring injuries, Duffy spent significant periods of the 2013 and 2014 seasons out of the game.
He made his debut for the Fremantle Football Club in round 20, 2014 against Geelong following some good form in the WAFL for Peel.
Prior to the 2017 season, however, he announced his retirement from Australian to train to become an American football punter.
[7] Duffy earned GPR Analytics National Punter of the Year in 2019 with an NCAA leading 98.30 GPR Punt Rating[8] Duffy was drafted by the Toronto Argonauts in the fourth round of the 2021 CFL Global Draft on 15 April 2021.