For the first time this season Liverpool are facing questions over their own title credentials.
Man Utd capitalised on their rivals’ poor run to leapfrog them in the table with a hard fought win over Burnley on Tuesday.
Suddenly the balance has shifted, if albeit perhaps momentarily.
But the onus is very much on Liverpool to come out fighting after surrendering top spot amid a series of lacklustre displays.
United have got momentum, and more crucially it seems Ole Gunnar Solskjaer now knows his best XI, all of whom are fit and available.
Meanwhile Liverpool’s injury crisis continues to cause havoc, and no one is feeling that more so than boss Jurgen Klopp.
Here are five questions facing Klopp ahead of Sunday’s clash.
1. Who plays at centre-back?
Joel Matip still doesn’t appear to be back in training, suggesting it is unlikely he will be available to face United.
That leaves Klopp with the difficult quandary of who to pair with Fabinho in the back line.
His confidence in Nat Phillips and Rhys Williams appears to have diminished following the results over Christmas.
Williams’ performance against Tottenham last month offered promise, but he was caught out against West Brom and would face a tough afternoon against Rashford and co.
Captain Jordan Henderson hardly excelled in the role either, and his drive and energy were missed from Liverpool’s midfield.
Georginio Wijnaldum can play there, as too can Andy Robertson, though neither are ideal or particularly plausible options.
It’s one that Klopp may lose a bit of sleep over.
2. Does Thiago start?
He’s back from injury, he’s got minutes under his belt and he’s a world class operator.
The question should be a simple one to answer, but Klopp will not want to risk the Spaniard if he’s not completely ready.
Thiago didn’t have the best of games against Southampton and was one foul away from a second yellow card for much of it.
He was back to his best against Villa’s kids in the cup, but Paul Pogba and co will be a completely different kettle of fish.
It will come down to whether Klopp feels Thiago can have more of an impact against tired legs later in the proceedings, or if he is required from the get go and is prepared to bank on him.
Much could depend on whether Henderson is deployed at centre-back, while James Milner or Curtis Jones could also play instead.
But Thiago – if ready – could well be the difference.
3. Youth or experience?
However Klopp shapes up his side, unless he picks either Williams or Phillips in his back four, he’ll have another decision to make in midfield.
In the probable event that Henderson drops in to centre-back, with Thiago sitting deep in front, that leaves one other space to fill next to Wijnaldum in the three.
Jones has been a revelation this season, and was Liverpool’s best player in their last top six tie against Tottenham.
He’s never started in a game of this magnitude though, not with so much focus and added pressure.
The teenager is more than capable of dealing with it, but Klopp could stick with experience and go with Milner instead.
Milner’s been there, done it, got the T-shirt. And has provided solidity in these kind of fixtures before – something that Liverpool will need with Bruno Fernandes buzzing around.
Alex Oxlade-Chamberlain is also available, though after his performance against Southampton, his inclusion in the starting XI would be a surprise.
4. Stick or bust?
It won’t be lost on Klopp that this is Liverpool’s only opportunity in their own hands to regain the advantage over United until May.
The Reds boss is all too aware what losing ground in the title race can mean in the long run, after seeing his side miss out by a point in 2019 despite going unbeaten from their defeat at Man City in January and winning all their last nine fixtures.
This season is very different, but the problem is United are in a rich vein of form, while Liverpool, well, aren’t.
Klopp’s men have looked sluggish, laboured in their approach to goal, and the Matip-shaped hole has brought an unwelcome uneasiness to their back line. Even Alisson was shaky against Southampton.
So does Klopp accept his team are not at the levels of last season and set his side up cautiously? A draw would not be the worst result after all, while a defeat is simply unthinkable.
Or does he tell his troops to go for the jugular, take no prisoners and urge them to play their usual free-flowing attacking game in the hope his side spark into life and take the upper hand again?
5. Plan B
Well, we know Klopp doesn’t really do a plan B.
But he does have the option to change things from the bench if required.
Diogo Jota is still sidelined though, meaning Klopp will have to put faith in some of his other lesser-favoured charges – something he’s not particularly fond of doing.
Among them could be Xherdan Shaqiri, whose arguably finest hour for Liverpool was a brace against United just over two years ago.
Takumi Minamino got on the scoresheet in the 7-0 drubbing of Palace the other week, and generally looked lively, while Divock Origi has a penchant for coming up with goals at the right moment.
Oxlade-Chamberlain could also have an impact if he joins the fray late on.
That’s if Klopp is prepared to let them loose.
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