Massimiliano Allegri is hopeful his leading scorer will be fit for Tuesday's battle with the Catalans, while calling on his team to play with courage despite their injury woes
The Italy international missed Saturday's 1-0 victory over Udinese due to a thigh injury, while his status for Tuesday's match remains in question.
Allegri refused to rule out the possibility of the 23-year-old being fit to feature against the Blaugrana, explaining that he will wait closer to kick-off before deciding whether the forward will play.
"Balotelli is doing better," the Rossoneri boss told reporters.
"We'll check on his condition in training today and we'll see if he can be called up.
"The physical condition of the side is improving. We all have to work in the same direction."
Despite a growing list of injuries, Allegri believes his team are capable of repeating their 2-0 home victory over the Catalan giants in last season's round of 16 first-leg clash.
"It will be a fascinating game for everybody," the former Cagliari coach mused.
"We need to play with courage and sacrifice against the best team in the world to get three points and increase our chances of qualifying.
"I believe that tomorrow Milan will perform well, we must try to make as few mistakes as possible. Barcelona will control the ball more than us, so we have to play a game similar to last year's."
Milan sit second in Group H with four points from two matches, while Barcelona have a 100 per cent record.