A year before his debut McCarthy was playing local football for Highett and working in marketing; the West Coast Eagles took him with pick 1 in the 2025 Mid-Season Rookie Draft off the back of a standout Richmond VFL stint, and he responded with a club-record 31 disposals on debut. The 188cm half-back has since signed a contract extension. He has played 32 AFL games and kicked 1 goal.