Pictures have emerged showing Mario Balotelli in an apparent bust-up with manager Roberto Mancini at Manchester City's training ground.
The pair had to be separated after Mancini reacted to Balotelli catching Scott Sinclair with a late challenge.
Although officials have attempted to play down the incident, which two sources have said was a "storm in a tea-cup", pictures indicate a clash of tempers, with Mancini appearing particularly animated and angry.
Members of the City coaching team dragged Balotelli away from his boss, who was shown to be pointing at the forward following the initial tackle.
Mancini is also seen grabbing Balotelli's orange bib as he made his feelings known, even though the younger man towers over the former Italy international.
City refused to comment on Thursday, citing the public access around their training ground as the reason why what they regard as a relatively minor incident should cause such a stir.
Questions are bound to be asked of Mancini at his press conference to preview Saturday's FA Cup tie with Watford though, with not just Balotelli's behaviour but his own coming under scrutiny.
Mancini has previously been criticised for indulging Balotelli far too often.