The last time Manchester United scraped a 1-0 FA Cup win at Nottingham Forest was a watershed moment for the club.

A poacher’s goal by Mark Robins was enough to upset Brian Clough’s high-flying side, and save Alex Ferguson’s job. Or so legend has it.

United went on to win the trophy, then the European Cup-Winners’ Cup and the rest is history.

Fergie was at the City Ground again on Wednesday but whether Casemiro’s late header will be seen as a similar landmark is doubtful: up next are Manchester City at The Etihad.

Still, it was a vital win after the gut-wrenching late loss to Fulham had ended a five-game winning run.

You just know the knives would have been out again for Erik ten Hag if the Dutchman’s sole route to silverware had been closed off.

As it is, the Red Devils have a quarter-final home tie with Liverpool to look forward to, and they will hope that Jurgen Klopp’s kids will have shown their age by then.

But on the more pressing matter of gaining points to qualify for the Big Boys’ League, there is less room for optimism.

City will have had an extra 24 hours to rest after their own Cup exertions, but that, laughably, is the least of their advantages.

Where City were overwhelming, United were underwhelming.

Erling Haaland whetted his appetite with five goals at Luton where Kevin de Bruyne claimed four assists.

Ominously, the pair look to be back to their lethal best and they’ll be licking their lips for Sunday night.

Sitting next to Fergie at Forest was Sir David Brailsford, otherwise known as ‘Mr Marginal Gains’ until he, too, was knighted.

A man with such an obsessive attention to detail will be aware that catching up with their neighbours requires something more than marginal.

New co-owner Sir Jim Ratcliffe is even talking about starting afresh and building an entirely new stadium – such is the state of Old Trafford.

He’s lucky the team is not in such dire need of repair.

There are outstanding kids here, too, notably Alejandro Garnacho and Kobbie Mainoo, but there are also structural weaknesses and leaks.

And even with the parts of undisputed quality, you have to question the buying policy.

Real Madrid trousered more than £100m when they sold Raphael Varane and Casemiro who were already close to their sell-by dates.

Casemiro was brilliant for much of last season but this time is a mere shadow of his former self.

Varane has spent more time injured than fit and has never reached the classy heights he did in Spain.

You can’t imagine City signing veterans at such inflated fees. But the Glazers hadn’t a clue and, as usual, United had to pay a levy for their ignorance.

The good news is that you can’t imagine Ratcliffe paying that kind of money either.

But Devils’ fans should not expect a magic wand. Reviews into every aspect of the club take time, but he’s made a decent start.

Fronting up to the media last week was something the family in Florida never did.

And he’s already pulled off a coup by pinching Omar Berrada, the mastermind behind City’s rise, as club CEO.

His attempt to lure the equally highly-rated Dan Ashworth as sporting director from Newcastle has hit the buffers with Ratcliffe refusing to pay the £20m fee the Geordies are asking.

It’s a message the new regime won’t be held to ransom as Ed Woodward always was, but you suspect a compromise will be reached.

United fans should be encouraged by these early moves.

Nope, they’re not household names, but by going to two of the club’s greatest and richest rivals, and taking their movers and shakers is a sign United are once again punching their weight.

Both men in question were begging to go there.

Fergie’s United would have gone for Harry Kane and Declan Rice in the summer transfer window, but the rules prevented that.

But at least now they have – or will have – people in power who know what they’re doing.

And they know that City have at least a decade’s start on them. But even Pep Guardiola recently said that “United will be back.”

But not yet.

Indeed, if Haaland and De Bruyne continue their Luton rampage, Sunday’s scoreline could be embarrassing.

Whoever United put up against Haaland, he is likely to be barged over while you suspect that Casemiro may get the job of cutting the supplies from De Bruyne.

The aging Brazilian has always been a bit of a hatchet man when needed, but he will have to be careful – an early yellow would only play into City’s hands.

City appear to be hitting their straps at the right time for the long run in.

De Bruyne has an amazing 12 assists after missing the first six months of the season.

With both their superstars back to form, only Liverpool and Arsenal have hopes of stopping them.

That said, the champions have shown more vulnerability at the back than in recent seasons as well as a lack of pace in the centre.

You could see the occasional Garnacho-led breakaway troubling them but apart from that, United are not likely to see much of the ball.

Andre Onana has improved of late and that was one reason for the five-game winning run.

But you feel the keeper will have to produce more of his ‘Inter Milan form’ to keep City at bay.

The Cameroonian’s inconsistency was one of the main reasons for United’s struggles until recently.

Sunday will be his ultimate test, but such is City’s current firepower that he could play a blinder and still concede plenty.

It’s hard to see anything but a convincing City win: if not, United fans just might be talking about another landmark moment.

The views expressed are those of the writer and do not necessarily reflect those of FMT.