Milan will have a hard time against Fiorentina, but they will not lose. The league champion is now clear, but the competition with Juventus for the 2nd place continues.
My prediction is that Milan will win this game and keep the points difference with Juventus.
The current odds are for the result of this game are like below:

This is a quite close game that's for sure. The point gap between these teams shouldn't misguide people. I wouldn't place a bet on a side here but both teams to score could be a really good option for this one. Fiorentina beat them in their last two games against Milan home. The scores were like 2-1 and 4-3 so over 2.5 goals could be another nice option.
Milan aren't catching up with Inter from now on when we look at the standings. They would like to maintain the second position until the end of the season at least. While Juventus are playing against Lazio away Milan had better get a good result here.
The odds for both of them don't seem much different and choosing one of them seems a little risky even though the odds for both of them look very tempting even though Milan has been in a good trend lately but the bookie has put the odds quite close to Fiorentina so it's quite difficult to determine which one of them will win. Statistically, in this match, both have almost equal chances of a draw and this match can still happen.
AC Milan no longer has a chance to overtake Inter because the difference between the two is very far, the only thing AC Milan can achieve this season is to be in 2nd place to maintain that place because Juventus is still Milan's biggest rival in the fight for second place. Juventus also experienced a match that was not much different from Milan, namely against Lazio, even though in the points table Lazio and Fiorentina were in close positions, which means their performance was almost the same. Milan and Juventus both played away against them.