The Italy international could miss the Rossoneri's upcoming Serie A clash with Juventus because of a problem sustained in Wednesday's Champions League loss to Atletico Madrid
The Italy international was substituted in the second half of the first leg of the Rossoneri's Champions League last 16 tie with Atletico Madrid on Wednesday.
Milan have now confirmed that the former Manchester City forward will miss Sunday's Serie A trip to Sampdoria on Sunday and faces a race against time to be fit to face leaders Juventus seven days later.
A club statement released on Thursday read: "AC Milan wishes to communicate that in yesterday evening's match [against Atletico], Mario Balotelli suffered a shoulder injury.
"The player visited with professor Alessandro Castagna today [Thursday] and the recovery time has been estimated at around 10 days without unforeseen complications.
"Mattia De Sciglio also suffered an ankle injury in yesterday’s match and the player's recovery time will be decided on in the coming days based on medical tests."
Milan were beaten 1-0 by Atletico, with Diego Costa heading home the winner at San Siro with just seven minutes to go.