Thilthorpe had already played 15 SANFL senior games for West Adelaide before he was drafted, and he marked his Round 6, 2021 debut against Hawthorn with 5 goals from 16 disposals. The 201cm forward can also take the ruck. A knee injury in the 2024 pre-season cost him most of that year, though he returned to kick 15 goals from seven games. He has played 99 games and kicked 154 goals.