The former Inter Milan forward has scored in every game of the last five with OM.
"I played Mario when he was 17," he said.
“He's a player like everyone else with incredible quality. He's still quite young and it depends on him. If he does well and works hard, he'll get his chance.
“Ultimately we'll have to call 23 players and someone will have to stay out. For now we're only thinking about the Euros, which we want to qualify for, and then we'll see what happens.
“Italy's a country where football is always at the centre, and it's unlikely that we won't have anyone to call up."