Forward makes his first start for the Rossoneri since recovering from heart surgery, with Mesbah and Gattuso also given rare starts
The 29 year-old will partner Zlatan Ibrahimovic in the Milan attack, with Kevin Prince Boateng taking his place behind the front two. Veteran midfielder Gennaro Gattuso comes into the midfield to replace Antonio Nocerino, while Algerian Djamel Mesbah comes in at left-back for Luca Antonini.
Mid-table Siena make three changes to the side that drew with Bologna in midweek. Coach Giuseppe Sannino reverts to a 4-man defence, with Cristiano Del Grosso coming in and Gaetano D’Agostino dropping out.
Siena (4-4-2): Brkic; Vitiello, Rossettini, Terzi, Del Grosso; Grossi, Vergassola, Gazzi, Brienza; Larrondo, Destro
AC Milan (4-3-1-2): Abbiati; Abate, Bonera, Yepes, Mesbah; Gattuso, Van Bommel, Muntari; Boateng; Ibrahimovic, Cassano