The Daly Star says the Italy international used some ripe language when he was substituted by Mancini in the 69th minute.
He appeared to mouth "f*** you" on his way off, then muttered behind his manager's back after sitting down, sporting a scowl that millions of parents of rebellious teenagers will have instantly recognised.
Mancini was turned away from Balotelli as the striker walked off, but later he was clearly angry with the 22-year-old.
"A player is never happy to leave the pitch, but if Mario had scored he'd have stayed on the pitch," said Mancini.
"I'm the manager, I decide and I cannot play with four strikers.
''I think he should be disappointed with the chance he missed, not about leaving the pitch in the last 25 minutes.
"It was a bad chance he missed. We haven't scored a lot of goals this season, this is the problem."