The striker was handed the suspension after insulting match officials following defeat to Napoli on Sunday.
Allegri said: "Players must think just about playing and not think about the decisions of the referees. There are situations that go beyond the rules of good manners. When the match is over it is over. Balotelli was wrong and that's that, he must grow-up. He is a world-class player and an Italy international so he should set an example. He has been fine up until Sunday so hopefully he has learnt his lesson.
"Balotelli and Higuain are two different players, the Argentine is a real out and out striker while Mario does best when attacking along the flank. He needs to improve his team-work and we have to remember that this is first year as the main player and should be playing in three games a week. We started the season thinking about the playoffs, we got into the Champions League and we started well with Celtic. In the league we are a bit further back but we have time to get back."