The Italy international believes that the Rossoneri did not show the right attitude on Sunday and has set his sights on victory against Napoli next weekend
The Rossoneri went two goals up at the Artemio Franchi but eventually had to settle for a 2-2 draw, despite the fact that Fiorentina were playing with 10 men from the 40th minute on following Nenad Tomovic's dismissal.
"Aside from some dubious individual decisions, our approach - mentally speaking - to this game was wrong," Montolivo was quoted as saying on the official Milan website.
"Maybe we thought the game was over before it was and it’s a shame as this was an important match."
The midfielder then looked ahead to next week's match versus Napoli and stressed that Milan want victory in order to stay clear of Fiorentina in the race for third spot.
"We definitely want to win against Napoli and we’re asking for a hand from the fans. They’ve always been behind us and we hope they’ll be with us this time as well.
"We have a six-point lead on Fiorentina and our objective is to finish in the top three."
Milan are trailing second-placed Napoli by four points ahead of next weekend's match.