Larson made his first grade debut for North Sydney in his only game for the 1987 NSWRL season, a Round 9 match with Penrith at Penrith Stadium. Starting from the bench, Larson scored a try on debut but the Bears still went down to the Panthers 19-10. 1988 saw Larson playing mainly Reserve Grade for the Bears and he only played two games for the season, including his debut in the starting side playing second-row in North Sydney's 6-38 loss to league newcomers, the Newcastle Knights.