 A Sampdoria youth product, Ganz started his professional career with the Sampdoria senior side in 1985, making his professional debut in Serie A on 14 September 1986; he won a Coppa Italia with the club in 1988.He later moved to Monza in Serie B during the 1988–89 season, before helping Parma A.C. to Serie A promotion from Serie B during the 1989–90 season.He spent two more seasons in Serie B, and later played for Brescia, finishing the 1991–92 Serie B season as the top goal-scorer, with 19 goals, and helping the club win the league title, earning promotion to Serie A.