Gilardino was sacked just weeks into Balotelli's arrival as a free agent earlier this season. The striker hasn't seen action since under Gilardino's successor, Patrick Vieira.
He told La Gazzetta dello Sport: "It was a challenge for both of us, I would have tried to help him. In the last part of my career I had many doors closed in my face, I know how much anger and desire for revenge an athlete has.
"I had perceived this in Mario, I hope he can demonstrate it."
On the success of former Genoa striker Mateo Retegui with Atalanta, Gilardino also said: "Yes, for two reasons: when he arrived in Genoa from Argentina, the fact that he had never stopped was important, and then the fact that he was able to work with a maestro like (Gian Piero) Gasperini right from the summer retreat."