[citation needed] He furthered his football by playing in the TAC Cup with the Dandenong Stingrays as well as becoming a member of the AIS-AFL Academy.

[6] He was named on the half-forward flank of the Under 18 team of the year and played alongside future Greater Western Sydney teammates such as Dylan Shiel, Matthew Buntine, Tomas Bugg, Taylor Adams, and Jeremy Cameron.

[7] Treloar was recruited by Greater Western Sydney as an under-age selection prior to the 2010 AFL draft[8] and played with the Dandenong Stingrays and the Noble Park Football Club during his junior career.

[13] He was touted by former Hawthorn forward Dermott Brereton as the next Mark Ricciuto, saying that he had the potential to "be an absolute elite player in the midfield and be top five in the comp with his ability, with his skill set and with his want and desire for the game.

[28] In 2018, Treloar won the Anzac Medal,[29] and later played in the losing grand final to West Coast.

As the 2020 AFL season drew to a close, rumours began to circulate that Treloar would seek a move to Queensland, after his partner Kim Ravaillion signed a one-year deal to play netball with the Queensland Firebirds and temporarily relocate to Brisbane with the pair's daughter.

He returned to play from Round 21 onwards, which started with 3 consecutive losses to finish the regular season as the Bulldogs fell out of the Top 4 by just 0.5%, thereby losing the "double chance".

In the 2024 AFL season Treloar played 22 Home and Away games in addition to the Bulldogs' elimination final loss to the Hawks, throughout which he kicked a career high 16 goals and led the league for average disposals.