Marotta faces his old team this weekend.
Garrone said: "We need to forgive in order to be good Christians. Even if, in certain cases it's tough to forgive.
"It's true we left each other on very bad terms. He had decided on a new experience? So be it. He wanted to take Del Neri with him? Very well. But he couldn't also take Paratici from me, knowing that we were counting on him.
"You don't behave like that. But it's water under the bridge. We have Gasparin and Di Carlo, and we'll do well.
"Marotta is one of the best sporting directors in Italy. He is an honest person in a world that isn't diamond pure."