Born in Treviglio, Lombardy, Castellazzi started his career at Torino Calcio.
Due to financial difficulty, the team originally promoted to Serie A in 2005 but expelled, a new entity, Torino F.C.
[7] In June 2011 Sampdoria gave up the remain 50% registration rights to Foligno.
Castellazzi only played 9 times for Foligno in the first half of 2011–12 Lega Pro Prima Divisione.
At the same time Lecco got Castellazzi, Matteo Cavagna and Ivan Merli Sala.