The striker hit a hat-trick against Sampdoria on the weekend.
But his international career has stalled after failing to show up for Azzurrini duty while called up by the Under-19 side in May 2013.
"If someone makes a mistake then it is right that they pay for it," Di Biagio told Stop & Gol.
"I'm convinced that before constructing footballers, we have to build men.
"He certainly made a mistake with the U-19 side and it is no coincidence that he was suspended by the Federation as a result.
"He has to ask for forgiveness and understand that he needs to take a backwards step, at that stage we can meet him with open arms as he is an intelligent kid and a great player.
"He doesn't need to say sorry to me, he's done nothing to me, but he needs to do it for himself so that he can grow."
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