City's 20-year-old Italian is back in England after two weeks in America recovering from a knee problem.
Fitness race: Balotelli could miss City's showdown with United on Saturday
But City coach David Platt suggested the match against the Premier League leaders may be too soon for him.
Platt said: 'He's not trained much yet. Mario came back on Monday, he's continued with his rehab and so far so good. It's certainly not a given that he'll be on the bench against United.'
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