Can Man City with the treble that Fergie described as 'impossible'?

Think 'treble', and the mind swiftly turns to 1999, a throbbing Nou Camp and the out-stretched right boot of Ole Gunnar Solskjaer deep into added time.

Manchester United's unprecedented triumph two decades ago is rightly regarded as the pinnacle of English footballing achievement, and for another season, it will remain an unrivalled one.

But for its architect Sir Alex Ferguson, there was one treble haul that he'd written off as 'impossible': The domestic treble.

There is more than a hint of irony, then, that the club Ferguson once derided as merely 'noisy neighbours' now stand on the verge of becoming the first side to win all three major honours in English football in a single season.

Manchester City have swept all before them this season and have made it abundantly clear that a clean sweep was their intention from the get-go.

While quadruple hopes were dashed by a VAR television monitor last month, Pep Guardiola has shown an unwillingness to compromise on the strength of his side against even the lowliest of opponents, underlined by a 9-0 win over Burton en route to League Cup success, and a 7-0 destruction of Rotherham on the way to this Saturday's FA Cup final.

As a result, City are a win away from achieving what Ferguson never believed possible.

The Scot's scepticism was well founded. With European competition taking precedent, sustaining a squad to fight on four fronts was not, he would come to believe, not possible.

But he did try. During his 26 years in the dugout at Old Trafford, the Red Devils went closest to completing the domestic clean sweep - twice.

In 2009, having already secured the League Cup and ahead in the Premier League, United tumbled out of the FA Cup to David Moyes's Everton in the semi-finals on penalties. Fifteen years previously, United's treble hopes were shattered by another familiar Old Trafford face, as Ron Atkinson's Aston Villa triumphed in the League Cup final at Wembley.

It was that failure, in 1994, that rendered the domestic treble a moot point for the Scotsman.

A miserable defeat to Galatasaray in the second round of the Champions League on away goals in November left Ferguson's runaway league-leaders only domestic honours to fight for, and fight for them they did.

United had fielded strong sides throughout their Coca Cola Cup run and by the time they reached the final they were already clear at the Premier League summit, while their opponents Aston Villa, were out of form and resigned to a mid-table finish.

Inspired by revelation Eric Cantona and invigorated by bleary-eyed prospects like Ryan Giggs and Roy Keane, anticipation was growing as United's relentlessly drove towards a treble. Villa were given long odds.

'What we have just seen is all part of a master plan before the United game,' said Atkinson, attempting to make light of three dispiriting defeats in eight days ahead of the March final.

'They've had us watched in our last three matches and they won't have a clue of what to expect from us.'

With three trophies in his sights, Ferguson played his strongest hand. Only Peter Schmeichel was absent - an enforced change due to suspension - while the rest of his starting line-up would all be Double winners by the end of the season.

But two goals from Dean Saunders and another from Dalian Atkinson shattered United's treble hopes, and left Ferguson resigned to the prospect that it just would not be possible to repeat.

'All this talk about a unique treble has not come from us,' a dejected Ferguson said after the match.

'I was always concerned about coming unstuck in a cup tie through any kind of unlucky break and that's how it has turned out.'

United rallied to win the FA Cup - inspired by a 119th minute equaliser from Mark Hughes in the semi-finals to force a replay against Oldham - before closing out the title race with the highest points total the Scot would ever accrue at Old Trafford; Ninety-two from 42 matches.

But the Coca Cola Cup calamity had a lasting impact on the United manager.

The following season, in United's second round clash with Port Vale, Ferguson drew the ire of the Football League by fielding the kids. He made nine changes, four of which were entirely unenforced.

That moment marked a turning point. From this point on, Ferguson would make a habit of using younger players in the League Cup. A year after Port Vale, United's youngsters were dumped out of the same competition by York City, after a chastening 3-0 home defeat.

For the Scot, the domestic treble was not impossible because of the difficulty of the League Cup, or the relentlessness of the Premier League.

He felt no side could balance being competitive in Europe with three further competitions on home shores.

It was this logic that would undo United in 2009, when David Moyes - and referee Mike Riley - thwarted the prospect of at least a domestic treble.

United were on course for a quadruple that season and with a Champions League semi-final against Arsenal just a few days away, Ferguson gambled by resting Wayne Rooney, Cristiano Ronaldo and Edwin van der Sar for their FA Cup semi-final showdown with the Toffees.

Lacking their razor sharp teeth in front of goal, United laboured to a goalless draw as young trio Danny Welbeck, Darron Gibson and Federico Macheda failed to break down a resolute Everton side.

In the shoot-out, Rio Ferdinand and Dimitar Berbatov both missed, gifting the Toffees a shot at FA Cup glory against Chelsea.

Ferguson rightly raged at the inexplicable decision by referee Riley not to award a penalty for a clear foul by Phil Jagielka on Danny Welbeck mid-way through the second period, but ultimately, he was punished for his caution.

It is an example that perhaps Guardiola has heeded.

Indeed, the Catalan coach has also resisted the urge to take any chances on selection during his side's all-conquering campaign, fielding his best assets whenever possible. In the FA Cup alone this season, City have scored 20 goals from just five matches.

In the transfer market, with the exception perhaps of Fernandinho's holding midfield role, City made sure they could fight on multiple fronts by ensuring no individual position does not have strong options in reserve.

Ferguson's scepticism does not ring entirely hollow, though. Like United in 1994, City have been aided to an extent by their European slip-ups.

Their defeat to Tottenham in the quarter-finals of the Champions League allowed a domestic focus that proved essential to seeing off the phenomenal fight put up by Liverpool - who forced City to win an extraordinary 14 consecutive league matches in a row.

But, whereas United crashed out in November, European defeat for City against Spurs came in April. The Citizen's only previous loss, while still competing on all four fronts, came at Newcastle, three months prior.

Five years on from defeat in 1994, Ferguson showed winning trophies on multiple fronts was possible, becoming the trailblazer behind which his side's local upstart rivals now follow.

But whereas he believed a domestic clean sweep was not possible while fighting on the continent, Guardiola has sought otherwise.

In 2009, after defeat to Everton, United went on to beat Arsenal in the Champions League semi-final, but were denied another treble by Guardiola's Barcelona in the final in Rome.

Fast forward a decade, and the Catalan stands ready to go where no one, not even Sir Alex, has gone before, and win a treble of his own.