De Jong says Balotelli can come through his problems and live up to his self-styled tag of being one of the best in the business.
De Jong said: "It's not all about Carlos Tevez.
"He is a great player for us and is the captain of the club, but we have a lot of good other players here and you can see that with Balotelli.
"I've told Mario, 'You've gotta keep smiling when you score'. Not everyone can score goals - I still haven't scored in almost two years here - so Mario needs to keep smiling when he manages it.
"He's a lively guy. Sometimes his body language is not what you would want to have on the pitch, but he is a winner and he always wants to win and score. He is quite critical about himself. If he loses the ball or doesn't score a great opportunity, he criticises himself.
"But he is a top bloke and, at 20, he is still very young. We are all there to help him to settle in, though.
"He's not a loner at all. Everybody is with him and tries to help him because he is still a young lad. He has learned a lot in the last couple of months.
"He is prepared to work hard for the team and he knows what to do to be successful."