The 39-year-old also backs the Nerazzurri's decision to retain faith in coach Andrea Stramaccioni.
"Keeping Stramaccioni says a lot about the club's intentions for the future," he told Gazza Offside.
"But that move needs to be followed up with the arrival of a few new players because it is clear that something has been missing this season.
"If the squad remains pretty much like it has been, then it would be hard for Inter to target the Scudetto in 2013-14."
Materazzi played for Inter from 2001 until 2011, winning Serie A five times and the Champions League once.