AC Milan defender Daniele Bonera could miss up to three months after sustaining a fractured kneecap in his team's 2-1 win over Valencia in the International Champions Cup on Saturday.

The 32-year-old started 13 games in Serie A last term for the Rossoneri, and his absence leaves the club short on options in the center of defense.

With Bonera out, Milan has a shortage at the position with only Philippe Mexes and Cristian Zapata serving as natural central defenders.

Saturday's match also saw Milan winger Robinho leave the game with an injury as he sustained a thigh strain and limped off after 27 minutes.

The Brazilian is expected to miss the next two weeks and could be unavailable when Milan opens its Champions League campaign on Aug. 20 in the first leg of a playoff.