Claiming a season is a marathon not a sprint is a cliché so hackneyed it evokes ire from even the most servile of interviewers when hearing it uttered from a manager’s lips. The fact remains however that the tired old axiom is as true today as it’s ever been and there can be no doubt that Manchester City – previously so spritely and capable of unleashing the most elegant of bombasts without so much as breaking sweat – have recently hit the dreaded ‘wall’.

They began the campaign in fancy dress, waving to the crowds and eschewing the proffered paper cups of water. Now each pound of the pavement is laboured as their legs fill with lactic acid. They are increasingly running on empty with the Mall in sight.

From August through to Jan they could have given Barcelona a good crack. Now for 150 minutes of a two-legged Europa Cup encounter they found themselves outclassed by Sporting Lisbon, a good side certainly but one that would have been brushed aside with imagination, swagger and haughty disdain mere months ago.

As the title challenge reaches its intensive climax the sulphur and magic that once came so naturally is now summoned in dribs and drabs through sheer force of will.

It’s a frustration Paul McCartney must feel every time he sits down to write a song.

David Silva is a pertinent case in point. The jinking, weaving majesty has deserted him at the worst possible time. The will o the wisp is now a whisper and the ironic stadium cheer that once met a stray ball from his boot has become a communal grimace.

Last night such toils even affected the newbies. Since his arrival from Roma David Pizarro has been a consummate puppeteer from deep. Against Sporting he all-too-often got his strings messily entangled as he sought out Hollywood balls to Johnson that were never going to reach their target.

The persistent long diagonal punts were particularly exasperating considering the team selection as Mancini front-loaded the bases with creativity who were regularly by-passed and made redundant. The line-up in itself hinted at desperation – an uncharacteristic attempt to force the issue from the off against a side with only a single goal advantage – but if a trio of ball-players are to be employed in the City engine room it was surely wise to play through there?

Without a midfield cornerstone taking simple balls from the centre-backs and orchestrating patient passages of possession – Barry was injured but De Jong brooded on the bench – there was little to no structure and consequently the rhythm was unfamiliar and discordant. Worse still it meant Yaya was shackled, his driving forays sorely required to break through the stubborn and well-organised Portuguese resistance.

It was the most fractured, abject performance at the Etihad for some considerable time.

Up front Balotelli continued to act like a petulant toddler waging a one-man war against everything around him which admittedly is a premise that would make for a great Sunday afternoon comedy on ITV2 but in reality is hardly what City need right now. Aguero drifted, Silva was present in body alone whilst Johnson was his usual ineffective self whenever he is a starter.

It was the most fractured, abject performance at the Etihad for some considerable time and City were made to pay heavily by conceding twice.

With an impossible four goals required the tie, barring a miracle, was over.

A chain of events led to that miracle so nearly occurring. Firstly Mancini rectified his costly error by bringing on De Jong which instantly gave City shape. A strike by Aguero prompted Sporting – who were high-fiving in premature celebration as they sauntered off at the break – to instinctively curl into the foetal position and the ensuing waves of attacks ignited hope and belief in both the team and fans.

Even as a neutral (witnessing Liverpool in Istanbul for example) I love such moments when the tide begins to turn and an unlikely comeback suddenly appears possible. It’s charged with electricity and one of the most thrilling aspects in the game.

To what end City’s magnificent fightback re-energises their former self will only become clear next Wednesday as they stage their next critical test against Chelsea.

But perhaps, following a gradual decline into fatigue, the constant obligation of attaining three points and pressurised struggle, this go-for-broke fun-fest was exactly what was needed. If only to remind them that when they attack with such relish and intent City are a formidable, uncontainable force.

Two further goals set up an Alamo finish and with seconds remaining Big Joe ran up for a set-piece and headed into the far corner only to see it tipped away by his opposing number. Visions of Jimmy Glass, Carlisle and riotous celebrations flashed across the minds of all those present. I was on the floor, a loud groan of anguish giving way to a manic laugh.

City were only a Hart beat away from a sensational finale to top all others. It may yet bring back to life a team that was beginning to flat-line.