Milan are facing a defensive crisis ahead of their Serie A match against Siena at the Stadio Giuseppe Meazza this weekend.
The Rossoneri, already without the suspended Philippe Mexes, are expected to be shy of three other centre-backs.
The club have today confirmed that Daniele Bonera picked up a right thigh problem and subsequently missed this afternoon’s training session.
Colombian veteran Mario Yepes, meanwhile, has twisted his right knee which will require medical tests.
Cristian Zapata was also absent from the session at Milanello as the summer signing from Villarreal has a fever.
Midfielders Massimo Ambrosini and Sulley Muntari could be used as emergency centre-backs by boss Massimiliano Allegri given that he can presently only count on Francesco Acerbi in that role.