Roberto Firmino the glue that bound Liverpool as they tore through Manchester United

Kenny Dalglish was clothed in merriment, his laughter lighting up the screens in the press tribune at Old Trafford.

The footage cut to his great friend and football foe, Sir Alex Ferguson. The look of embarrassment, astonishment, and resignation on the face of the man who made Manchester United larger than life told the story of how staggeringly they’ve shrunk.

The scoreboard read 5-0 to Liverpool with 50 minutes on the clock, as Mohamed Salah marked adding a hat-trick to his Best in the World folder when the cameras cut to the faces of legends of this fixture, of this sport.

Neither could believe what they were witnessing: Dalglish delirious and his counterpart dazed like the team he was backing. Paul Pogba hadn’t even been sent off yet to compound the omni-shambles.

Manchester United, bloody hell. Unrecognisable to Fergie, unable to live with a Liverpool who were nowhere near their best nor their very, very good.

They didn’t need to be.

For so long, the hosts have operated under nostalgia. They’ve used it as a tactic, a tonic, a tagline. Here, it was laid to rest. Ole Gunnar Solskjaer cannot hark back to the glory days when his team have been so savagely undressed and have spent the season walking to this very point.

On commentary, Gary Neville admitted as much while contorting in every which way not to highlight how badly United are coached. “It’s what l said: The minute they play a proper team, this is what will happen.”

Liverpool were everything their opponents were not: clinical, smart, possessing a clear defensive structure and plan to expose the space they’d be gifted out wide.

This was symbolised best by the performance of Roberto Firmino. He dropped into midfield to overload Scott McTominay and Fred.

The Brazil international muddled Harry Maguire and Victor Lindelof with his movement, pressed hard, linked play incredibly, was efficient when on the ball and closed off United’s passing lanes.

“He played outstandingly well,” Jurgen Klopp said. “Mo gets a lot of attention and rightly so, but Bobby, people with football knowledge know how important he is.

“I’m pretty sure when he finishes playing, people will write books about how he interpreted the false nine position. I won’t say he invented it, but the way he plays it looks like it.

“The way he played was absolutely insane. Bobby knows how well we appreciate what he is doing.”

Firmino, serenaded for 10 minutes by the travelling fans post-match, was doing whatever the team needed from him and was an example of how an individual that works for the collective will always ultimately trump the brilliance of an individualist.

United have relied too heavily too often on the latter to carpet their deficiencies.

Firmino and Liverpool pulled the rug to show the extent of what has been swept under it.

They do not have on-pitch identity, a blueprint, a cohesive structure or… a clue.

And so the first United-Liverpool game in front of a full house since January 2020 was coloured with lengthy chants of “Ole’s at the wheel” – from the away end.

If the home side’s display wasn’t painful enough, that mockery will have cut deep.

Dalglish applauded, Ferguson dropped his head. They couldn’t believe what they had seen, but was this really a surprise?

Manchester United, bloody hell.