Cagliari boss Roberto Donadoni is looking forward to Milan's visit to Sant'Elia on Thursday, but insists he won't go easy on his former club.
The 47-year-old spent a decade at Milan and won every major club honour, including three Champions League titles and six Scudetti.
Interviewed in La Gazzetta dello Sport, Donadoni said: "I had a long and important career with Milan. But now what counts is doing well on January 6."
Asked if it will be billed as a clash between himself and Milan boss Max Allegri who is making his first return to Cagliari following a two and a half year spell in Sardinia, Donadoni replied: "This is the choreography. The players will give it substance. We can't make mistakes against the League leaders.
"I don't know Allegri personally, but the good results show him to be right. He is competent and professional."
Looking ahead to the match itself, Donadoni said: "The absence of Zlatan Ibrahimovic can change Milan's attitude on a tactical level. The team loses an advanced reference point and can become more compact and unpredictable. In addition, they have Cassano too."
Reflecting on his first few months in charge of Cagliari, he added: "Three victories in five games is positive. But now there is work to do to give continuity to our results.
"In January we have Milan, Parma, Palermo and Roma: games that can give a turning point to our season."