Milan are forced to use Mattia De Sciglio in central defence after losing Mario Yepes, Daniele Bonera, Philippe Mexes and Robinho.
The Rossoneri welcome Siena to San Siro on Sunday afternoon in their first match of 2013.
However, there are problems for Massimiliano Allegri, as Mexes sits out a ban, while Yepes has a knee problem that will keep him out for two to three weeks.
Bonera was hoping to make his comeback, but limped off during training with a new muscular problem.
“Tomorrow in central defence we’ll have De Sciglio, who is not a centre-back but has the qualities to take that role,” said the Coach.
Djamel Mesbah, Cristian Zapata and long-term absentee Nigel De Jong also miss out.
Robinho is not included in the squad as he has not been training regularly. He had hoped for a transfer to Brazil, but Milan confirmed negotiations with Santos broke down last night. 
Milan squad for Siena: Abbiati, Amelia, Gabriel; Abate, Acerbi, Antonini, Cristante, De Sciglio; Ambrosini, Boateng, Constant, Emanuelson, Flamini, Montolivo, Muntari, Nocerino, Strasser, Bojan, El Shaarawy, Niang, Pazzini
Think you know your Italian football? Share your knowledge, tips and comments to win cash prizes in OLBG's tipster competition  - £11,000 to be won monthly!