Man Utd 0-0 Liverpool: Reds' lack of threat is a worry - Alan Shearer
Liverpool are back on top of the Premier League but it is clear all is not right with Jurgen Klopp's team at the moment.
They had a big opportunity to go to Old Trafford and beat an injury-hit Manchester United side, but ended up producing a very disappointing performance.
When I think of Klopp's Liverpool teams at their best in the past couple of years, they are so dangerous because of the way they press sides, and put the opposition under pressure with their energy and the speed of their attacking play.
We saw none of that at Old Trafford, where they offered so little going forward that United could have played without David de Gea, who was never tested in goal.
That surprised me, because it must have given Liverpool a boost beforehand to see that Nemanja Matic, who has been one of the key players in United's revival under Ole Gunnar Solskjaer, was out injured.
Seeing United forced into making three first-half substitutions should have lifted them too. They should have been thinking: 'This is our chance.'
But instead they offered next to nothing.
They were far too safe and never looked like opening United up - and I think it could come back to haunt them.
If they had gone there and won that game, irrespective of their performance, it would have sent out a big message to Manchester City.
Instead, it was a brilliant weekend for Pep Guardiola's side, who won the Carabao Cup and saw their title rivals drop points.
Only time will tell whether it truly turns out to be a poor result for Liverpool or not but, looking at it now, it certainly gives City confidence about the level that the leaders are at, and their ability to catch them.
'Liverpool still solid, but they will need more than that'
Liverpool were very flat at Old Trafford, but it was not the first time they have been poor in the past few weeks.
Pressure will have played a part, regardless of what their manager or their players have been telling us about how it is not affecting them.
Tiredness is not an excuse, because this is only their fifth game in the past five weeks and they have had sunshine breaks in Dubai and Spain during that time.
But something is wrong because they have drawn three of their past four Premier League games, and were held at home by Bayern Munich in the Champions League too.
It is their attacking form - or lack of it - that concerns me more than those results, though, because they have just not looked themselves in some of those matches.
Yes, they are still solid at the back, but they are going to need more than that to hold off this City side in the title race.
Klopp has to hope this is just a blip, but something has to change because they are just not good enough going forward at the moment.
What is wrong with the front three? 'A lack of service'
I don't think we are at the stage where Klopp will drop one of the front three. In fact, I would be surprised if he does, because this is not just down to them.
Whether he is scoring goals or not, Roberto Firmino plays an important role in linking Liverpool's play together, so they will hope the ankle injury that forced him off against United is not a serious one.
It is hard to criticise Mohamed Salah too much because he is still scoring a lot of goals, even though he has not looked as sharp as usual in recent weeks.
Like Salah, Sadio Mane needs service if he is going to shine, and that is what Liverpool have been lacking of late.
They do not have the ability in midfield to play that quick and incisive pass to produce something out of nothing in a tight game, which is what is costing them at the moment.
That was obvious at Old Trafford because just staying compact was enough to keep United out of trouble.
They were never asked any serious questions by forwards running in behind or stretching play. Everything was in front of the United back four and they coped with it very easily.
What next? 'Liverpool need a performance as well as three points'
What happened against United means Liverpool's next test, against Watford on Wednesday, becomes a must-win game.
We will be saying that a lot in the next few weeks and the same goes for City too when they take on West Ham on the same night because, at this stage of the season, results mean everything in the title race.
But right now Liverpool badly need a big performance as well as the three points to get themselves back on track.
They have to go to Goodison Park to face Everton next weekend and they will barely get a chance to breathe in the Merseyside derby, so this is not an easy week for them and it will only get harder from here.
Alan Shearer was speaking to BBC Sport's Chris Bevan.