There was a moment with just over an hour played when Jordan Henderson picked up possession in the centre-circle. He looked up, waited, looked up some more and eventually, having no other option, floated a long ball forward. Chris Smalling won the header against Sadio Mané and another Liverpool attack withered into nothingness.
The impetus of November and December has ebbed away, and although Liverpool still have the title in their own hands there is a distinct sense that the momentum is now with Manchester City.
There were specific frustrations here given how United spent the entire first half in a blur of reorganisation, their technical area transformed into a triage station, but the truth is that, since the 5-1 win over Arsenal at the end of the December, Liverpool have not played with the sort of attacking verve for which they have become renowned under Jürgen Klopp.
There was the 3-0 win over Bournemouth, it’s true, but there may not be a better opponent for a top side to play, certainly at home: the game will always be open and is very unlikely to degenerate into a battle. This was a fourth draw in their past five games for Klopp’s side, and only the second time they have failed to score in two successive games this season.
There's a tendency always to want what you do not have, to believe that the blanket is always slightly too small, but there have been times this season when Liverpool's midfield has seemed distinctly functional. Nobody can realistically doubt that Liverpool did well from the sale of Philippe Coutinho, who wanted to go anyway, and whose fee helped pay for Virgil van Dijk, but equally there have been times this season when they have lacked a little of the invention he might have brought.
Lacking in guile
That was particularly obvious, for instance, in the away games against Napoli and Paris Saint-Germain in the Champions League. Perhaps if Alex Oxlade-Chamberlain had not been ruled out with a cruciate injury he could have provided a little thrust, but the fact is that a team that set up with Henderson, Fabinho and Georginio Wijnaldum as their midfield three will always risk being a little lacking in guile.
Which raises the question of how Liverpool last season, even after Oxlade-Chamberlain had suffered his knee injury, never seemed so flat as this. The answer perhaps lies in pressing, which Klopp once declared the greatest playmaker in the world. Play high up the pitch, keep the opponent under constant pressure and mistakes will be made and chances will come. It was a theory that had worked for Klopp at Mainz and at Borussia Dortmund and was doing so at Liverpool as well.
The problem was that it came at a cost. Liverpool finished last season in a state of exhaustion, their squad stretched to the absolute maximum. It didn't take Raymond Verheijen to diagnose the problem – although the Dutch coach did, repeatedly, on social media. Liverpool were running too hard.
So Klopp took the logical step of easing back. Liverpool have, by and large, not pressed with anything like the same intensity this season. The result has been fewer injuries and an improved defence, but the change of approach has also highlighted the lack of midfield flair since the departure of Coutinho.
Out of sorts
None of which would necessarily matter were the front three firing as they did in those final months of last season. But they are not.
Roberto Firmino has been struggling with a virus recently, and left Old Trafford on crutches after sustaining an ankle injury.
Mohamed Salah has seemed oddly out of sorts in recent weeks, at times bafflingly so, like Billy in one of those frequent periods in which his magic boots had gone missing.
Mané, with four goals in successive games before the draw against Bayern, has been left to carry the burden, but given how deep United played, there was never likely to be space behind the defensive line that he could attack with his pace.
But to speak of individuals, perhaps, is to miss the point. The interaction between the front three is not what it was. There is not the same sense of a telepathic understanding. In part that’s to do with opponents sitting deep so the opportunities for those thrilling sweeping counters are diminished, but only in part. A tentativeness has crept into Liverpool’s attacking play that has ramifications across the pitch.
If the movement is not so slick as it should be, there are fewer targets for Henderson to hit, which perhaps explains why so often he resorted to hitting it long.
Klopp spent most of the game in a fury, and Henderson pointedly snubbed him after being substituted, suggesting that he felt a disproportionate amount of the criticism had been directed at him or that he was frustrated at being the player to make way for Xherdan Shaqiri.
The Switzerland international can bring a spark, but by the end the visitors ended up with Daniel Sturridge and Divock Origi up front, trying to pick them out with aerial balls.
A draw at Old Trafford can never be a poor result and if City lose here it will look a very good one.
But the bigger issue for Liverpool is perhaps more the performance and the general lack of penetration.