Perhaps Brendan Rodgers should have been more audacious from the start. There's no exact science, nobody could say for absolute certain that the outcome would have been different, but then you think back to how timid Liverpool were in the first half and it's tempting to wonder what might have happened if they had shown even a touch more ambition.

It's true, as Rodgers said, they can be encouraged by those parts of the game when Manchester United suddenly looked a little vulnerable and the crowd was starting to get restless. But sporadic glimpses are not enough.

The gap between these two great old rivals can be described more accurately as a gulf, coming in at 24 points, and it was a dishevelled attempt from Liverpool for the most part to find out whether United's defending might be as generous as everyone had been saying.

"We're not 24 points behind in terms of quality," Rodgers said. Yet Old Trafford gets a lot of managers passing through who talk enthusiastically about brief parts of matches and promise their team will learn from it, get stronger and that it will be different in the future. It rarely is.

The bottom line is the team from Anfield were two goals down before they got their act together to offer the semblance of a threat and, before that point, had barely threatened at all.

Luis Suárez wriggled and hassled but was isolated too often. Raheem Sterling and Stewart Downing should have been supporting him but rarely left the game's edges. Daniel Sturridge's introduction at half-time offered more impetus and, in hindsight, Rodgers might regret not putting him in from the beginning.

Sir Alex Ferguson said afterwards that United had played as well in the first hour as any other time he could remember this season. It helps that they have a player, Robin van Persie, who can score goals from any angle, or any distance, and is surely going to clean up with the footballer-of-the-year awards for a second successive season.

Daniel Welbeck was an elusive, coltish opponent, sometimes clumsy on the ball and erratic with his finishing but constantly on the move, difficult to pick up, deceptively strong. Rafael Da Silva has morphed from an error-prone kid into a man. Patrice Evra had his best game of the season.

Liverpool, all the same, were obliging opponents. They managed only one attempt at goal in the first half and it wasn't even on target. Instead, the moment that really stood out came seven minutes before the break when their leading scorer had the ball at his feet and four United players around him. Not one other Liverpool player was in the penalty area or even particularly close. It encapsulated the way they had played.

Suárez never stopped working, always wanting the ball, but too many of his colleagues struggled to have any form of impact. Rodgers has described Joe Allen as "the Welsh Xavi" and it's clearly the case that he is an accomplished keeper of the ball. Not here, though. Allen picked a bad day to have, quite possibly, his least distinguished game in Liverpool's colours.

Michael Carrick, meanwhile, played with the kind of refinement that must have reminded the watching Roy Hodgson that surely he should have tried to get him back into the England team before, rather than after, Euro 2012.

The number-crunchers at Opta say the Premier League is 20% faster than five years ago. It's fast, frenetic and doesn't let up, and it takes a special player to see the right pass at this level and have the ability, almost every time, to play it with the perfect weight. Carrick, so long an elegant frustration, has taken a long time getting to the stage where he is controlling matches from his position in midfield but what a damning indictment it is of English football that someone of this calibre has started only 16 England games in 12 years.

He was at the hub of just about everything during those moments when José Mourinho, watching Real Madrid's next opponents in the Champions League, might have been forgiven if he had experienced a rare flicker of insecurity.

Mourinho's body language was already unusual. His hood was pulled up and there was a look in his eye that said: Do not disturb. If his team lose to United he will almost certainly lose his job and for long spells, particularly in the first hour, they certainly gave him something to think about.

Ferguson's side are not flawless. Antonio Valencia is going through a loss of form at a bad time bearing in mind the man he replaced, Ashley Young, left Old Trafford on crutches. David de Gea's habit of turning shots into the path of opposition players is also something that needs working on. United also have that recurring habit of making life unnecessarily difficult for themselves, be it letting in soft goals or racking up miss after miss.

Ferguson spent the final exchanges in classic pose: on the touchline, chomping on his gum, looking at his stopwatch. Three times, he pulled back his coat sleeve during the four minutes of stoppage time. Liverpool's flickers of recovery had left him craving the final whistle when, in reality, it should have been a lot more straightforward.