The Liverpool midfield dilemma Jurgen Klopp must solve against Manchester United

It's the biggest dilemma Jurgen Klopp faces ahead of a potentially season-defining afternoon for Liverpool at Old Trafford.

At the back, it's pretty straightforward. Defensive talisman Virgil van Dijk will return refreshed and ready after his midweek Champions League suspension.

With Dejan Lovren still struggling, Van Dijk is set to partner Joel Matip on Sunday afternoon with full-backs Trent Alexander-Arnold and Andy Robertson either side of them.

Up top, barring any late fitness issues, Klopp will unleash his usual three-pronged attack and back them to deliver after they fired blanks against Bayern Munich.

Mohamed Salah, Sadio Mane and Roberto Firmino will certainly have more space to operate in with Manchester United certain to show greater ambition than the German champions.

However, in the centre of the park, the situation for Liverpool is considerably less clear.

We're building up to Sunday's game against Manchester United HERE

Remarkably, in the eight matches the Reds have played since the turn of the year, Klopp has fielded a different midfield combination in each of them.

To a large extent that's been enforced with injuries, illness and suspension forcing Klopp to shuffle his pack. But all season the manager has adopted a horses for courses approach in that particular department.

Liverpool kicked off 2019 with Jordan Henderson, Gini Wijnaldum and James Milner starting there in the narrow defeat to Manchester City.

On a night when Klopp made wholesale changes for the FA Cup tie with Wolves, he went with a trio of Milner, Naby Keita and Curtis Jones.

There was a switch to 4-2-3-1 for the win over Bournemouth with Wijnaldum and Henderson together before reverting back to 4-3-3 with Henderson, Fabinho and Keita in action against Crystal Palace.

With Henderson pressed into duty as a makeshift right-back in the stalemate with Leicester, it was a two-pronged centre midfield of Wijnaldum and Keita.

Adam Lallana joined Fabinho and Keita in there for the unimpressive draw at West Ham.

The combination of Fabinho, Keita and Wijnaldum worked perfectly in the rout of Bournemouth as Liverpool regained some fluency and controlled proceedings.

But the visit of Bayern prompted another re-think with Fabinho needed at centre-back. The return to full fitness of Henderson proved to be timely as he shone alongside Keita and Wijnaldum.

Now Old Trafford awaits. Realistically, it's Henderson, Keita, Wijnaldum, Fabinho and Milner vying for three places with Klopp expected to stick with the 4-3-3 system.

Getting that balance right will be crucial against a revitalised United who have won 11 out of 13 games since Ole Gunnar Solskjaer took over. United are likely to field a midfield trio of Ander Herrera, Nemanja Matic and Paul Pogba.

Fabinho should be one of the first names on Klopp's teamsheet. The Brazil international deputised brilliantly at centre-back against Bayern but Liverpool missed his dynamism further up the field.

The former Monaco man has the temperament as well as the quality to handle the hostility that awaits the Reds at Old Trafford. They will need his controlled aggression and ability to feed the front three.

Henderson certainly deserves to keep his place after a man-of-the-match display against Bayern. 

The Liverpool captain looked fit and strong as he made more passes in the opposition half (41), regained possession more often (eight) and completed more tackles (four) than any of his team-mates.

“Hendo did a brilliant job there,” Klopp said.

“It was unbelievable how many balls he won back and stuff like that. It was a fantastic game from him – but that’s actually what we expect as well.”

So that leaves one spot. Milner has the wealth of big game experience but he would appear to be the outsider having not started a Premier League game in midfield since City away in early January.

Picking between Keita and Wijnaldum is a tough one. Keita has enjoyed a highly encouraging month and has clearly benefited from getting a run in the side with five straight starts.

There were flashes of real quality from the Guinea international against Bayern but it wasn't sustained. He faded in the second half and made way for Milner.

Wijnaldum has been a model of consistency this season and is arguably the safer pair of hands, especially in a contest of this magnitude. It's a big call for Klopp.

When United were humbled 3-1 at Anfield back in December, his trust in Fabinho, Wijnaldum and Keita was rewarded.

But this is now a very different United in different surroundings and what's at stake is considerably greater.

The Premier League title race won't be decided at Old Trafford on Sunday, but the gap between success and failure on the day will be vast.

Klopp has won at the Etihad, Stamford Bridge, the Emirates and Wembley, but a triumph at Old Trafford has so far eluded him.

Put that right when Liverpool play their game in hand on Manchester City and his side will be three points clear of the champions with 11 games to go. The psychological boost would be immense.

Fall short against a United side hell-bent on wreaking the Reds' title dream and it would cut deep. City would be in the ascendancy.

Getting that right blend in the centre of the park will dominate Klopp's thoughts over the coming days.