Victories over Manchester United and Chelsea not enough to assure Roberto Mancini will remain Manchester City manager

Maybe in the end, after near a billion pounds spent, the big decision will be based on the sentiments of those whom Manchester City have known are their lifeblood, all along. The supporters sang the name of Roberto Mancini yesterday and left in delirious delight at the prospect of him bringing more silverware to their trophy cabinet, so it was hard to countenance the idea of the two most important men on the Italian's landscape taking the decision to part company with him.

Chelsea looked like a team who had been to Russia and back in midweek but Khaldoon al-Mubarak and Ferran Soriano, City's executives, were presented with evidence that their own club have travelled a fair distance in football, too. You can measure out in matches against this west London opposition their accelerated assault on the high echelons of football. When the Abu Dhabis had arrived and marked their ownership with what was supposed to be a signature signing in Robinho, five years ago, the £26m man scored on his debut and Chelsea simply went off and scored three more. Even when an electrified Craig Bellamy helped them score four at Stamford Bridge a year and a half later it defied much of the evidence about which of the two clubs was the supreme among the monied set. The pendulum has swung now.

The City fans sang, as they like to do, that "they're not really here" but they don't journey to Wembley wide-eyed any longer. Gone are the Wembley spotters making proclamations 10 minutes before the Pendolinos reach Euston. And though their team's fast, rat-a-tat-tat passing in its purest form gave way to a second half when anything could have happened and the supporters fell into periods of wretched, tight tension, they will be back here soon. After victory at Old Trafford on Monday, it has been a signature week for the manager.

You imagined when Mancini's waved acknowledgement for the singing of his name that the supporters would consider the manager's position to be sacrosanct, though the argument – made in these pages last week – that he is indeed the man for City's onward journey did not meet with universal agreement. The players don't give the universal impression that they want him, either.

"Some people don't, even though I do," one said privately this week, which was hardly a ringing endorsement and in the decision to reduce Joe Hart to the substitutes' bench and prevail with Costel Pantilimon as his goalkeeper for the FA Cup, Mancini hardly acknowledged yesterday that his relationship with the Englishman is sorely in need of repair.

The Hart decision seemed one which was destined to bite Mancini at times yesterday. It was a dreadfully ominous moment, midway through the first half, when Pantilimon made to run out to take Juan Mata's floated free-kick, flapped at thin air, and was stranded as Eden Hazard executed an awkward volley back in, which Vincent Kompany was required to head off the line. There were several occasions when the goalkeeper simply seemed to dive late – he thumped into the turf after Demba Ba's effort was nestling in the net – though there was also his excellent work, diving at the feet of Mata to flick the ball from him when Chelsea fought back with a will which made anything possible. Such are the margins on which a manager's decisions can look inspired or incomprehensible.

It would have helped Mancini's hold on his position had his players maintained the dominance which made the first 30 minutes of yesterday seem little less than a hammering. But if there is one reason why City have not been able to command the Premier League for perhaps 18 months, it is that they lose something when their freedom to play their passing game denied them. They don't have the pace, the dagger blow, the shock tactic, then. Don't try telling that, though, to the supporters who flooded north last night in the knowledge that they will probably be making this journey next time with expectation, not in mere hope, of reclaiming the FA Cup.

We will also soon be back into the territory of waiting for an imminent expression of confidence, or otherwise, in this Manchester City manager – three years after the last one followed the club's failure to qualify for the 2010-11 Champions League. There was not much suspense, that time. "Let's be realistic. One of the challenges we faced was expectation," Mubarak said in May 2010.

Expectations are incalculably greater now and the truth about Mancini's future is far more difficult to discern from within the sanctuary of what has become an extremely secretive club. But yesterday revealed City to be a club who are still going places.