The Italian has admitted he will leave the club at the end of the season and highlighted injuries as a big reason behind the Rossoneri's failings this term.
Allegri took charge of the club in 2010 and won Serie A in his first season at San Siro, but the Rossoneri's fortunes since then have dipped dramatically.
Star men Zlatan Ibrahimovic and Thiago Silva were both sold to Paris Saint-Germain in the summer of 2012 and only a resurgence in the second half of last season secured Champions League football this term.
With the club already 17 points adrift of third place, Milan will need a miracle if the club is to repeat that comeback and Allegri has now admitted he is in the final months of his reign.
"I do not know who will be the new coach, but it is a problem that does not concern me. Of course, this is my last Christmas at AC Milan," the Italian said when quizzed over the possibility of former Milan midfielder Clarence Seedorf replacing him.
"I decided to stay on for another season. I liked the idea of staying on and finishing the job, but four years with one club is many."
However, the 46-year-old has refused to give up hope of leaving the club with a parting gift, by securing European qualification via the Italian Cup.
"It's very difficult. We are 17 points behind third place," he added. "But we have to chase and improve our position in the table. All this can serve well as an incentive to do well. There is still the Italian Cup, which is still gives us a good possibility to remain in Europe."