Zlatan Ibrahimovic has been ruled out of the Serie A clash between Milan and Juventus on Thursday (AEDT).
The 39-year-old striker has been sidelined since being substituted in the 3-1 win at Napoli on November 23.
The former Manchester United and Paris Saint-Germain star has missed seven league games for the Serie A leaders, although the Rossoneri have fared well in his absence, winning five and drawing two of those matches.
Stefano Pioli's side are alone in Europe's top five leagues in that they have not lost a top-flight match since the 2019-20 season was initially shut down from last March.
They head into the match with champions Juve at the San Siro knowing a win would move them 13 points clear of the Bianconeri, who are fifth with a game in hand.
Ibrahimovic had offered hope he could be fit to face his former club after recent injury trouble, posting training footage to social media on Tuesday (AEDT) with the caption "Tick tock tick tock".
Head coach Pioli, though, says the player is not fully fit and admitted to scolding him for causing a stir two days before the game.
"I told him off because, after that footage, I was peppered with phone calls," Pioli told reporters.
"He is better and he's working well, but he won't be in the game tomorrow."
Rafael Leao has performed well in Ibrahimovic's absence, scoring in the 2-1 win at Sassuolo and the 2-0 victory at Benevento in the past two and a half weeks, becoming the second-youngest foreign player to reach 10 Serie A goals for the club, behind only Alexandre Pato.
Pioli believes the 21-year-old's development is a sign of the way Milan have improved in the past year. The Rossoneri have taken 37 points from their first 15 league matches this term, the first time they have done so in the history of the competition in the three-points-per-win era.
“He’s growing a lot, he has characteristics that we must try to enhance in the right way," Pioli said. "The important thing is to see the will to grow and improve on a daily basis.
"All matches are opportunities to prove our worth. We have to concentrate on the game and raise our level because they are strong opponents with experience and they have been winning for years.
"We're showing we can play for it and we'll therefore play to win. We have scored 17 points more than last year. This is the right path, but we can't speak of a decisive match after 15 rounds."