Balotelli, 29, was subjected to racist abuse by Hellas Verona fans in a 2-1 defeat this month and threatened to walk off the pitch.
Verona were ordered by Serie A to play a match with a partial stadium closure, while the club banned head ultra Luca Castellini for 11 years after he defended the fans' actions in a radio interview.
Balotelli returned to the Italy fold in 2018 after a four-year absence but has been back in the international wilderness since a 1-1 draw with Poland last September.
Mancini, the coach who gave him his big break at Inter in 2007, insists he is eager to see Balotelli play his way back into the squad, but he will not call up the forward for anything other than his performances.
"Football is a sport and as such it must unite people and not get destroyed by those few who make mistakes," Mancini told reporters.
"I love Mario. I played him when he was a teenager. He is still young enough to give much to the sport, but for me it is important to state that if I am to call him up, it's because he deserves it and can help us.
"Then, after what happened, I could have called him up, as the [Italian Football Federation] president [Gabriele Gravina] said, but I think it's important I call him when he technically deserves it, not to send a message. He still has other chances.
"We are nearly in 2020 and skin colour... It is not very easy for some people to change their attitude, unfortunately.
"We called up some young players [instead] because from now until March we will not have the chance to see them live [for Italy]."
Italy are due to face Bosnia-Herzegovina and Armenia in their final two Euro 2020 qualifiers on Friday and the following Monday, respectively.
The Azzurri are already assured of a place at next year's tournament.