 He was recruited by Canberra from the Young Cherrypickers where he played as a junior.Mullins played on the wing, in the centres and also filled in at fullback during 1991, but an injury suffered in the Minor Preliminary Semi-final against Western Suburbs saw him miss a place in the Raiders Grand Final side that went down 12-19 to the Penrith Panthers.Mullins continued playing in the three-quarters before securing the Raiders fullback spot following the retirement of Gary Belcher at the end of the 1993.