Growing up in Melbourne’s northeast, Coffield played junior football with Eltham and was also a talented junior basketballer. He captained Northern Knights in the then-TAC Cup while completing his schooling at Whitefriars College. A Bulldogs supporter growing up, Coffield’s older brother Dan played in Richmond’s 2019 VFL Premiership.

Following a dominant NAB Under 18 Championships in defence for Vic Metro where he averaged 22 disposals, Coffield was drafted to St. Kilda with pick 8 in the 2017 NAB AFL Draft. Coffield made his AFL debut in Round 3 2018 AFL season, accumulating an impressive 18 disposals and kicking a goal against Adelaide. A dislocated shoulder towards the end of 2019 was a setback, but Coffield enjoyed a breakout 2020. Playing every game after the COVID-19 shutdown, his ability to intercept and successfully execute off half-back was a feature of his game and saw him finish fifth in the club’s Best and Fairest. Off the field, Coffield is a keen follower of NBA and NFL, and is currently studying a Bachelor of Arts/Commerce.