Drafted from the Sandringham Dragons with pick 49 in the 2023 national draft, Johnston played six senior games in an encouraging first season and kicked his first AFL goal in front of the West Coast Eagles' home crowd. The 185cm Victorian has spent much of his development in the WAFL, working to turn athleticism into a permanent senior spot. Delisted by West Coast at the end of the 2026 season, he has played 14 AFL games and kicked 4 goals.