The AC Milan striker was again embroiled in controversy over the weekend after blasting fans on Twitter following his dismissal for Italy against the Czech Republic.
"Balotelli has nothing to apologise for," said Barzagli.
"It is his Twitter account and he expressed his state of mind at that moment, even if afterwards he changed his mind.
"I would advise him not to write anything publicly in the heat of the moment straight after a game, but he was intelligent in realising he got it wrong.
"He has to grow up, that is true, but Mario is constantly under attack from everyone - opponents, referees and fans. He'll have to get used to it, because he knows that he's going to receive special treatment on the field."