There is something quaint about Manchester United, and Louis van Gaal, clinging to the venerable old FA Cup as if their season depends upon it.

Actually, it pretty much does.

The Red Devils are out of the Champions League, out of the Premier League title chase, and struggling for a top-four place. History tells us that when van Gaal goes to war with the press, he's on the way out, no matter how long that takes.

But this isn't about him, and it isn't, per se, about the meaning of the 147-year-old Cup.

It is about the way that United plays, which should be with the emphasis on Red Devils.

A Manchester United that doesn't dare to attack with devilment goes against everything that earned Alex Ferguson, and before him Matt Busby, their knighthoods.

Fergie's most succinct pre-match instruction to the likes of Ryan Giggs, Paul Scholes and young Wayne Rooney was simply: "Go for their throats!"

I've edited an expletive out of that, but you get the drift.

Busby's treatise was more softly spoken, but it had to do with the duty of privileged and talent footballers putting on a show for people who were rebuilding their lives after the Second World War bombing necessitated the rebuilding of Old Trafford.

In three words: Entertain the public.

As Rooney closes to within six goals of Sir Bobby Charlton's record 249 United career goals, his strike against Derby County on Friday night was right up there in terms of beauty.

The shots from Daley Blind and Juan Mata were clean and clinical, and so too was George Thorne's goal for Derby County in the 3-1 final score. And there was more than a hint of majesty about the way that Anthony Martial glided down the left wing on a wet and windy night in Derby.

"You ask if I have given more freedom to the players tonight?" said van Gaal, his eyes glaring back at the reporter who dared to ask it.

"I can't answer that question because you have answered it for yourself and your newspaper."

He paused, then continued: "They always have freedom from me."

And, saying it was a matter of confidence, and it also depended upon the opponent, United's Dutch manager concluded that he was going home to a nice bottle of wine.

"My wife is at home, and the wine is already open," he said. "I have received that from Ed Woodward, probably the most expensive wine."

That reference to Woodward, the executive who signed van Gaal on behalf of the American owners, the Glazer family, was King Louis' way of saying that for all the stories about Pep Guardiola dining out with Woodward (and about Jose Mourinho touting for van Gaal's job) the speculation is baseless.

Is it? The media is not making up the fact that months of grinding United performances, boring the fans, the players by the look of their faces, and, yes, the journalists who have grown up expecting cavalier stuff from United.

I'm far enough from van Gaal's company right now to reiterate that Friday night in Derby was very much more liberated than what we have been shielding our eyes from over much of this season.

Rooney's goal, his sixth in six games, belies those who think that, having turned 30, he has lost his zest for the game. He received the ball on the edge of the penalty box, controlled it with one touch, turned to face the goal, and struck it seamlessly with the inside of his right boot high into the far corner of the net.

Whether it is instinctive, or the end product of a life spent rehearsing such a finish, Rooney still has it.

Sure, he might be losing the top edge of his acceleration, but he's at the age where experience can help the mind to compensate for that. If the desire is strong, and it looks it, the United captain has plenty left in him to eclipse Charlton in the months, perhaps years, to come.

And he has growing accomplices. Martial, just 20, looks so elegant on the ball, so much in control, and on Friday so free to exercise our imagination. No Derby defender could cope with Martial, and we are looking at a player who might very well mature into a centre-forward rather than the left winger he appears to be at the moment.

In truth, Derby were outclassed, a division beneath United as the league tables show. To be sure, Thorne's equaliser made the Red Devils have to work hard to regain the ascendancy, but Blind's rare foray into attack to score, and then Mata's sure-fire side-foot near the end made it look comfortable.

It would have been wrapped up much earlier had United capitalised on chances set up by their enterprising young full-backs Guillermo Varela and Cameron Borthwick-Jackson.

The manager's vin rouge will taste smoother... until Tuesday when United encounter Stoke in the Premier League.

Van Gaal insisted every game receives "the same philosophy". It doesn't show, but it is fun to see United pinning such hopes on the Cup again.

This, remember, is the trophy that they failed to defend 16 years ago, following the historic Treble - Premier League, FA Cup and Champions League in 1999.

By the following January, United's fixture list was too crowded to fit in FA Cup ties. The club was pressured by the government, and the FA, to take part in Fifa's latest money-making competition, the Club World Cup in Brazil.

Why government? Because England wanted to host the 2006 World Cup Finals, and according to David Davies, the FA chief executive at that time, Fifa sources made it clear that if United failed to contest the Sepp Blatter's Club World Cup, then England could forget about hosting the World Cup.

As it happened, Germany, not England, won that bid. But pressure, including personal calls between Ferguson and Prime Minister Tony Blair resulted in United giving up the FA Cup without even defending it.

Today, it is United's last chance of domestic honour.