Coach of the Serie A leaders feels the inter-city derby holds more significance to the Nerazzurri in terms of the title race than it does to his own side
With just two points dividing the sides at the top of the Serie A table, Allegri has moved to play down the match, and rejected the notion that a victory would guarantee the Scudetto.
He claims the derby della Madonnina, the 176th in the fixture's history, is important, but not critical to the season's outcome.
"It's an important derby, but it's more important for them than it is to us," he told the press.
"We have been top of the league for 21 weeks and we knew we would not be able to win the league a month early, but we have to think we can get a result in the match as it is a very important game."
Allegri reiterated that even victory for his side would not mean that they could assume the title was theirs.
He continued: "We will be top until the first whistle, if we win we will stretch the lead to five points with seven games left.
"It would not be a bad lead, but it's also true we have only won one point from two games. I don't like speaking about how we have already won the title.
"You win the Scudetto if you have a one-point advantage at the end of term, so we have to treat each game equally as we move forward."
Leonardo's Milan history has caused a stir as it is his first match as Inter manager against his former employers, where a strained relationship with Silvio Berlusconi saw them part company at the end of last season.
Allegri concluded by commenting on his rival coach, saying: "It's hard to move from here to there, but things change.
"I cannot judge Leonardo, he made this choice. But, it would be hard to move there."
Click Play to see how the derby della Madonnina will finish according to EA Sports' FIFA 11 simulation.