The Sweden international was shown a red card in the second half of the match for slapping Aronica, an action which could earn him an automatic three-game ban if considered violent conduct.
"I am reading catastrophic opinions, but there was no violence involved," Galliani told Milan Channel.
"I think that Ibrahimovic will not be suspended for more than two matches.
"Aronica's gesture towards Antonio Nocerino? I saw it, the referee did not."
After the match, Milan coach Massimiliano Allegri admitted that Ibrahimovic deserved a red card for his action.
In case of a three-match suspension, the former Barcelona striker will miss the club's Serie A matches against Udinese, Cesena and Juventus.
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