It was a five-nil that felt like 25.

Such was the pain and humiliation suffered by Manchester United.

Throw in six yellow cards and one red, the boos, the fan exodus, Fergie’s face of thunder and Dalglish’s beaming smile, schadenfreude oozing from every pore.

It really can’t get any worse for the Red Devils than last Sunday. Or can it?

The fixture list suggests there could be more pain to come. Next up they’re at Spurs this weekend, Atalanta away and then Manchester City come visiting.

After the international break, it’s Chelsea and Arsenal.

But it was being thrashed at home by Liverpool that twisted the knife for anyone associated with the club.

The hated nemesis from just 50km away. Handing out the most excruciating of drubbings. And their fans taunting mercilessly as only Scousers can.

Yep, Liverpool taught United a brutal lesson last Sunday about many aspects of the modern game. Pressing, shooting, defending, coaching, recruitment…

But if United are to extricate themselves from the mess they’re in, they could learn something else from their north-west rivals: albeit achieved by accident half a century ago:

Break with the past.

It’s one of the hardest things to do when you have a past to be proud of, but history is weighing United down.

The sight of Fergie was telling. The great man turns 80 in two months and had he been in charge, the hairdryer would surely have blown at half-time.

But he’s still involved. It was his phone call that redirected Ronaldo from the noisy neighbours to his spiritual home.

Hailed as a sensational coup at the time, it’s beginning to dawn that the prodigal son’s return might not have been such a brilliant idea after all.

It may have broken the internet and boosted the share price, but it also destroyed the best-laid plans of Ole Gunnar Solskjaer.

The manager had planned all summer to make Jadon Sancho, his £73 million signing from Borussia Dortmund, his key man. Starting wide on the right, he would have licence to roam.

But suddenly he had to find a place for an all-time great with a licence to kill.

Ronaldo has delivered the goals but the team is no longer functioning as a cohesive unit. And Sancho has hardly had a kick.

According to reports, it was Ronaldo’s half-time rant that inspired the comeback against Atalanta.

The Portuguese legend’s arrival has its undoubted plus side, but it has undermined Solskjaer’s authority both on and off the field.

The Ronaldo swoop was instigated above his head with Fergie driving it.

The grand old man simply couldn’t countenance the thought of one of his favourite sons playing in the same town and wearing blue.

And Ed Woodward and the Glazers rubbed their hands at the anticipated commercial bonanza.

But a million new Instagram followers doesn’t get you points in the table.

Not only is the side looking like a bunch of expensive misfits, but the most expensive piece of the jigsaw doesn’t also appear to fit at all.

Thirty-seven in February, he was only ever going to be a short-term fix. But he’s very quickly become a spanner in the works.

Hindsight makes you wonder if it might have been better all-round if he’d gone to City.

Solskjaer himself is another throwback to a glorious era.

A super-sub hero as a player, he was a success as a caretaker but should never have been kept on – he simply hasn’t the credentials to be a top coach in a top league.

He doesn’t even take training and eschews the front line of the technical area.

And he has the protection of ex-teammates-turned pundits who cannot bring themselves to criticise an old mate.

This mafiosi omerta is another example of the United soul being stuck in the past.

Fergie was behind bringing him back too.

When Liverpool’s greatest manager, Bill Shankly, retired the club faced a similar dilemma of how to follow an immortal.

And, sadly, both Shanks and the club made a mess of it. He didn’t really want to go and still went to training even after Bob Paisley had taken over.

Paisley asked Liverpool to stop him. They did – but it was like banning God.

It was necessary, though, and Paisley, finally his own man, went on to become almost as great as Shanks himself.

Liverpool became even better winning the European Cup three times.

Tragically, eight years after quitting Anfield, Shanks died, many said, “of a broken heart”.

His post retirement years were sadly unfulfilled but if he ever did manage to look down from his heavenly seat, he would know that the club did the right thing.

Ferguson’s situation is very different. He’s enjoyed a full retirement, but he’s not been able to keep his nose out of Old Trafford and his influence is strong.

And as we’ve seen of late, although well-intentioned, it has not always been for the best.

United only have to look at themselves and what happened when Matt Busby retired with an office “upstairs”.

Players would go to him instead of the new manager – whoever it was – and United ended up being relegated. It took them many years to regain their stride.

Fergie doesn’t have an office – he doesn’t need one – but he is omnipresent. Unfortunately for United, with absentee owners, there’s no one on the board with the stature to stand up to him.

Amid the wreckage of a catastrophic Sunday, the biggest lesson is to make a clean break with nostalgia – no matter how painful it is at the time.

Smarter recruitment would be a start and that includes the manager.

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