Signed by Greater Western Sydney as an under-age recruit, Treloar was traded home to Collingwood before a late deal in the 2020 trade period brought him to the Western Bulldogs. A career-best 2024 earned the 185cm midfielder his first All-Australian selection, and after an injury-hit 2025 he returned through Footscray's VFL premiership side. He retired at the end of the 2026 season, having played 263 AFL games and kicked 158 goals.