Born in Forlì "comune", Emilia-Romagna, Bettarini spent his childhood at Buonconvento "comune", in the Province of Siena, Tuscany. He then spent his youth career at a local side of Staggia Senese, a village in Poggibonsi, in the Province of Siena. He was signed by Internazionale in 1990. After first being loaned to Baracca Lugo, Bettarini joined Serie B side Lucchese and played four successive Serie B seasons, including one at Salerno. In June 1996, he was signed by Serie A side Cagliari but the team were relegated in 1997.