The Rossoneri coach can understand why the club's ultras vented their fury after Saturday's 1-1 draw with Genoa but says the players need their support
The Rossoneri faithful made their displeasure known after Saturday night's 1-1 Serie A draw with Genoa by blocking all of the exits at San Siro in order to force the players and coaching staff to meet them face-to-face.
Kaka and Christian Abbiati eventually emerged from the dressing room and managed to calm the situation, and Allegri is now desperately hoping that the supporters will roar their team to victory in Tuesday night's crucial Champions League clash with Celtic in Glasgow.
"It's only normal that the fans are disappointed," the Rossoneri boss told reporters. "Everyone at the club is disappointed: the staff, the players, everyone. We have to do better but the fans have to be behind us.
"Too many times recently we have not performed. But let us see what happens. Serie A and the Champions League are two different competitions.
"We will make sure we are as well prepared as we can. But our main objective is to qualify for the next round of the Champions League.
"This is an important match even if a win is not absolutely decisive for us to qualify. They are strong and they play aggressively. It will be a great night but we will have to be good technically and tactically."
Milan will progress to the last 16 with a win if Ajax are beaten at home by Group H leaders Barcelona.