From Mazenod College and Central Under 18s at the 1994 national draft. He had a long grounding in the reserves before his debut late in 1996, playing in the final home and away round and then in a final. Steinfort had a fine 1997 playing as a tall on-baller, but he then suffered two injury-ravaged seasons starting with a hernia problem early in 1998. His form in 2000 was excellent and he polled the 10th most votes in the club best and fairest. He was keen to continue with Geelong, but left when contract negotiations could not be concluded. He had a steady and consistent first year at Collingwood and missed just four games due to minor ankle and leg injuries. Although Steinfort played in the 2002 Collingwood grand final side, he was later surprisingly delisted.