The Rossoneri coach says they need to get through a tough game against the Biancocelesti before turning their attentions to their Champions League second leg against Barcelona
With attention already on their Champions League last-16 second leg on March 12, the Rossoneri are in need of a win against Biancocelesti to boost their hopes of qualifying for Europe's top competition next season.
Milan are currently fourth, two points behind the Roma-based club in fourth place and a mere point ahead of city rivals Inter in sixth who they drew 1-1 with last weekend, and Allegri is aware of the importance of the upper-table clash.
"It will be a difficult game as it always is against the top teams," the 45-year-old told reporters at a press conference on Friday.
"They have a good defence and I do not think it will be a spectacular game, although I hope I am wrong.
"We have to do everything possible to win so that we have two good results out of three, and so we keep pushing up the table."
Allegri's men must travel to Genoa next weekend before moving on to Catalunya, but the Livorno-born coach says he will only start thinking about Blaugrana after this weekend's tie at San Siro.
"We will start thinking about Barcelona after this game," Allegri added. "We should have won against Inter and a win tomorrow will increase our chances of finishing in the top three.”
"Barcelona have seen off all [competitors] in the Spanish league, but they have lost to Milan and they lost to Real Madrid [on Tuesday], so in the one-off games they can be beaten."