He joined Viadana in 2003 and was also included in Italy's squad for the World Cup in Australia that year. He had his 2005 season disrupted by injury. In the 2008 Six Nations Championship, new coach Nick Mallett played Masi at fly-half, a role he had not played before but many experts believed this move was unsuccessful and he was moved to full-back for the start of the 2009 Six Nations Championship.