Premier League - De Jong warns errant Balotelli
The 20-year-old Italian this weekend irked manager Roberto Mancini, who hauled the striker off after he attempted a trick shot in the club's friendly against the Los Angeles Galaxy.
De Jong, who was particularly demonstrative in his remonstrations with Balotelli at the time, said in comments quoted in The Guardian: "I've played with some strange characters in the past but it's the first time I have seen that."
He added: "It is frustrating, and he has to iron out those issues otherwise it will be a waste of his talent. He has to realise that now.
"All his team-mates are here to help him but he's his own person and he is the only one who can change his ways."