It's emerged Raiola is pushing to have Donnarumma's contract rescinded over claims it was signed under duress.
Fontana told TMW: "The Donnarumma case? (Rino) Gattuso's gesture is something normal, Donnarumma is still a Milan player and Rino must always keep him at the maximum.
"I think the boy ended up in a bigger issue than him, at 20 years old you cannot have the maturity and the experience to manage certain things.
"The one who is bigger than him should give him serenity and instead this is not happening. After the summer it seemed that there had been a reassertion, but evidently there was not.
"I believe that Raiola is doing his job, Milan is not respecting his expectations. He thinks he's right, he's trying to legitimize his ideas."