El Shaarawy stormed down the tunnel instead of taking his place in the dugout when substituted in the second-half.
"El Shaarawy was annoyed when he left the pitch yesterday against Palermo, and I don't know why," said Antonini.
"He decided to go directly into the dressing room instead of sitting on the bench, and that's not the right thing to do.
"Amelia went after El Shaarawy, but I stopped him and told him that it was better to just let Stephan leave.
"The whole thing was cleared up afterwards though."