 A surplus for young Sampdoria, Along with Francesco Antonioli, Castellini were signed by Serie A newcomer Bologna in June 2006.This time at Serie B.The defensive duo made a contribution to the team to win promotion to Serie A again in 2008 by conceding the fewest goals along with U.S. Lecce, But Castellini was too old for the Italian top division and he just made 13 appearances.