Most of the things football managers say about their supporters can be categorised as lip-service. When Louis van Gaal thanked the home supporters at Old Trafford for the noise they had made as United won the Manchester derby, for once it sounded genuine.

Alex Ferguson always used to hurry away down the touchline at full-time, hunched and businesslike, as though he was already on his way to the next game. Yesterday, van Gaal ambled slowly towards the tunnel, gazing up at the rejoicing hordes. He was basking a little in the acclaim, and why not? Ferguson had 1500 matches in charge at Manchester United. Van Gaal will be doing quite well to reach 150. There won't be many days like this, so he's enjoying them while he can.

Apart from ten nervous minutes at the start and another five at the end, his team had dominated the match and inflicted the sort of beating that must have embarrassed even a collection of old pros as jaded and world-weary as Manchester City.

The City fans had been delighted by that first ten minutes. For the first time in weeks, their team really seemed to be trying. The exchange of passes between Clichy, Milner and Silva to create Aguero’s opening goal was exactly the kind of rapid, unpredictable combination play that had destroyed United in the equivalent fixture last season.

It was also the last we were to see of that sort of thing from City, who could not recover from the shock of conceding a quick equaliser to Ashley Young.

Young was the first of four United goalscorers, each of whom, at some point in the last 12 months, had been described as a misfit and written off. The most interesting case of these is Marouane Fellaini, who was the decisive player in United's first half recovery.

The long David de Gea clearance that led up to Young’s goal was flighted quite deliberately towards the target of Fellaini in the left channel, and though Zabaleta beat the Belgian to the ball, Ander Herrera was lurking in the Fellaini second-ball zone, like a beady-eyed seagull following a trawler, knowing that any minute now, sardines would be thrown into the sea.

Fellaini headed home the second himself at the far post. When he was substituted late in the second half, he departed to an ovation every bit as enthusiastic as the one accorded Juan Mata a few minutes before.

It was assumed at the start of the season that Louis van Gaal would have no use for Fellaini’s primitive skills. Instead, van Gaal has made use of his power and his attitude.

There is still the matter of those primitive skills. Moments before he scored his goal, he had given away possession with a clumsy pass. Players who can’t pass seldom become heroes at Manchester United.

Fellaini has at least redeemed himself after that terrible first season, and showed the other players that it is possible to win back the confidence of the manager and crowd, if only they can see you are trying. United’s staff will hope that Angel di Maria has been paying attention.

Few things in English football are as important as giving the impression that you are trying, as Yaya Toure and Manuel Pellegrini are finding out.

Toure might be puzzled to find himself the focus of so much criticism after City’s recent poor run. He could argue that City’s season began to fall apart at the precise moment when he left for the Africa Cup of Nations. City won five of the six games before Toure left, and just one of the six that he missed. He returned to a team whose confidence had already crumbled.

Toure has not played well since his return but it's hard to see how he can be held responsible for the poor performances of players like Vincent Kompany, Samir Nasri, and even Sergio Aguero, who had failed to score in six matches before Old Trafford.

Kompany’s decline has been the most dramatic because his previous standards were so high. The City captain recently complained that Financial Fair Play was restricting City’s ability to compete. Such carping overlooks the fact that City spent more than £30 million on a central defender, Eliaquim Mangala, who was not considered good enough to start against Manchester United. If Kompany is looking for reasons why City are trailing in fourth place, he should start closer to home.

Manuel Pellegrini is not the problem at Manchester City. However, Pellegrini’s cool reserve deceives some people into believing that he doesn’t care. English football likes managers who lose their temper. One recent newspaper column suggested Pellegrini ought to be a bit more like Brian Clough, explaining that Clough would display his ruthless edge by occasionally punching a player.

That’s not Pellegrini’s style. But with eight defeats in his last 15 games, he’s losing his grip on the job. You can understand why by examining the decision from the perspective of Txiki Beguiristain and Ferran Soriano, the two executives who will decide Pellegrini’s future.

If they hire a new manager who struggles to make an immediate impact, they can explain it away as an inevitable part of the rebuilding process. If they stick with Pellegrini and he fails again, that makes them look bad. So saying goodbye, unfair as it would be, is starting to look like the safer option.