Roberto Mancini faces yet more player unrest after it was reported that Adam Johnson initially refused to board the team bus after the Carling Cup victory at Molineux last Wednesday night. The winger was said to be angered by the Italian's public criticism, especially after a game in which he scored one goal and created another for Samir Nasri.

The 24-year-old was eventually persuaded on to the coach but, following the Carlos Tevez affair, the incident has further highlighted the problems Mancini faces in keeping his expensively assembled squad happy.

The City manager, however, said that he will not hold back from criticising the winger because he thinks the comments will make him a better player in the long run. In a post-match interview on Wednesday Mancini said that, even though City were leading Wolves 5-1, Johnson should have tracked back to stop Stephen Ward providing the assist for Jamie O'Hara. Mancini said he was "disappointed he doesn't put everything on to the pitch".

After Johnson had scored again against Wolves on Saturday Mancini defended his stance, saying it was a deliberate policy to provoke the player to greater heights. He added that the England manager, Fabio Capello, was of the same opinion and that Johnson could and should reach the same levels of performance as his team-mate David Silva.

"I am happy he is upset," said Mancini. "I love Adam. It is like with the children in your family. If you love your children, then sometimes you should be hard with them and Adam understands this. I say what I want because, if he were not a good player, then I wouldn't waste my time on him. But because he has everything, I don't want him stopping at this level. I want him up a level and then a level more.

"He has some characteristics that are different from other players and because of this he could become one of the top wingers in the game. If you have a top winger, you are going to win a lot of games. One versus one, he is incredible, every time he takes the ball out wide near the box, we can score a goal or at least have a chance."

Mancini's treatment of Johnson, whom he bought from Middlesbrough in his first transfer window as manager of City, called to mind comments from his predecessor, Mark Hughes, that the Italian was "autocratic". Hughes said of Mancini before the Manchester derby: "I am not sure if he indulges players, tries to get to know them or understand them. He never can put his arm around a player – he is not that sort of manager."

In bloodlessly removing Emmanuel Adebayor and Craig Bellamy, two of the most combustible footballers he inherited from Hughes, Mancini demonstrated his control of the dressing room at Eastlands even before the conflagration with Tevez that has dominated the start to City's season.

Mancini argued that his attitude towards Johnson came from a determination that the player should not fail. "I have seen so many players like Adam in my life, both when I played and since I have been a manager," he said, adding that Johnson had played with more discipline against Wolves at the Etihad Stadium than he had shown at Molineux.

"Sometimes players like Adam play very well in one game but only so-so the next. He should not think: 'I have scored a goal, this is enough.'

"He has played in the Premier League for two and a half seasons now and he has played for the national team. Fabio Capello and I are of the same opinion. A player like him should play well every game, like David Silva."

On Monday afternoon the City defender Kolo Touré will face an internal inquiry into the failed drugs test that brought him a six-month ban.