The Swede has confirmed they're in talks with Milan about a return to his former club next month.
But Materazzi told TMW: "He is 37 years old. For years, he has been one of the strongest, but he has a certain age.
"Milan may take him as an alternative to (Gonzalo) Higuain, but (Patrick) Cutrone is doing well. It could be a risky choice. If he arrives and does good to the team, congratulations to Milan.
"But if it comes and it goes bad for the three attackers?"