A 1-0 defeat to Juventus in Turin on Sunday night has piled the pressure on the Rossoneri, who now have the resurgent Viola breathing down their necks for a Champions League spot
The Viola recorded a remarkable 4-3 win over Torino at the Artemio Franchi during the afternoon, while the Rossoneri lost 1-0 to leaders Juventus in the evening kick-off in Turin.
With five rounds of the season remaining, Italy's third and final Champions League berth is clearly now well and truly up for grabs, but Allegri is backing his side to keep Fiorentina at bay.
"We are not worried," the Rossoneri boss told Sky Sport Italia. "We have lost our first game of the year. Now we must try to do well in the next games to hold onto third place.
"We know that Fiorentina are a good side. We threw away a match point by not winning in Florence despite being 2-0 up. No our calendar becomes easier. I am confident."
However, Allegri was still left counting cost of Milan's misfortune in Turin, with the Rossoneri losing both Christian Abbiati and Massimo Ambrosini to injury before gifting their hosts the game-winning penalty with a defensive mix-up between Ignazio Abate and Marco Amelia.
"It was an evenly balanced game in which we conceded very little to Juve," the former Cagliari boss mused. "It was a game that seemed destined to end in a draw, but then we were punished for our only error in defence.
"Unfortunately we have also lost two players to injury and even [Riccardo] Montolivo was not at his best, physically."
Allegri was keen, though, to defend top scorer Stephan El Shaarawy, after another lacklustre display from a player who shone so brightly during the first half of the season.
"He's a boy of 20 that has done very well up until now, but it's normal that there can be a dip [in form]," he argued. "Physically, he's fine, but he must understand these difficult moments can happen.
"The true value of Milan will be seen next season," Allegri added. "Then we will be know if we can compete with Juve.
"We have had a great second half of the season; but I hope we don't undo all that in the remaining games."