Liverpool's hopes of a title defence were savaged over the weekend after it emerged Virgil van Dijk is set to spend the rest of the season on the sidelines.
Van Dijk, who is the bedrock of the Reds' defence, sustained an ACL injury in a horror collision with Jordan Pickford in Saturday's Merseyside derby.
There was widespread condemnation of the Everton goalkeeper but the foul went unpunished at Goodison Park as Van Dijk was forced off, before going on to have a scan at hospital.
Van Dijk has been a leader for Liverpool and was crucial in their title-winning 2019-20 season.
Without him, and with Dejan Lovren sold in the summer, boss Jurgen Klopp finds himself short on centre-back options through to the January transfer window, when he is next able to make reinforcements.
Joel Matip - who was seen entering Spire Hospital in Liverpool on Saturday - and Joe Gomez remain the two options for Klopp, with midfielder Fabinho another capable of slotting into Van Dijk's position.
Outside of those three Klopp would need to turn to the youth ranks with 18-year-old Sepp van den Berg seen as next in line.
Van Dijk's absence is a huge blow heading into a Champions League campaign and continuing their title defence, but can they still defend their Premier League crown? And if they do need signings to plug the gap, who is on the market?
Sportsmail's experts give their take on what happens now for the champions...
MATT BARLOW
Can Liverpool win the Premier League without Virgil van Dijk?
Yes they can but it's going to be difficult because he is key to the way Liverpool have functioned during this very successful period.
Even with Van Dijk in the back four, there have been signs that this season will be more of a challenge, with points dropped against Aston Villa and Everton.
He is the man who organises the team, not only the defensive unit. He sets the line high because he has the pace and confidence to recover if necessary and this sets Liverpool on the front foot to win the ball in advanced areas.
His dominance in the air offers security from set pieces and his comfort and confidence on the ball means they can play from deep when necessary.
Should Jurgen Klopp look to buy a replacement in January, and if so, who should he go for?
Most of the Premier League managers have been looking for the next Van Dijk since Liverpool signed him from Southampton. They all want someone with speed and mobility and good in possession.
There are not many on the market and if they are proven at the top level they will cost more than £80m. Chelsea took Thiago Silva on a free. Manchester City went for Nathan Ake and Ruben Dias. Spurs couldn't justify £50m for Milan Skriniar and opted for Joe Rodon from Swansea.
There will probably be clamour for millions to be spent on Dayot Upamecano and Kalidou Koulibaly but can Liverpool afford this sort of outlay?
There is no guarantee a new signing, especially if coming into the Premier League from overseas, will slot smoothly into the system to replace Van Dijk and, when he is fit again, are they a viable pairing?
By the time the market is open again, Klopp will have a clearer idea, based on the form and fitness or Gomez, Matip and Fabinho, of precisely what he needs in central defence.
IAN HERBERT
Can Liverpool win the Premier League without Virgil van Dijk?
Yes.
Don't forget about the way the entire Liverpool team defend so relentlessly from the front and that most teams will need to score several times to beat them. It's not just Van Dijk who keeps other sides out.
Fabinho now comes into play as a hugely significant player. He proved an able deputy for Van Dijk when stepping in for him stepped in for him in the Champions League Champions League clash with Bayern Munich in February last year: a 0-0 draw.
Joe Gomez looks more vulnerable when Van Dijk is absent. He wasn't convincing in December's Club World Cup semi-final against Monterrey in Qatar, when Van Dijk was rested. So Fabinho will need to be the defensive leader.
Van Dijk's absence should mean Liverpool adapting their extremely ambition high line and operating slightly more conservatively. Pushing both full-backs on so much is a big gamble, as we saw at Villa Park.
Should Jurgen Klopp look to buy a replacement in January, and if so, who should he go for?
Yes.
Despite the fact they can succeed without Van Dijk, Conor Coady's huge development at Wolves, with his full England debut coming last week, makes the notion of Liverpool moving to bring him back to his home city and boyhood club an entirely viable one.
There is no doubt that Liverpool's defence has looked sloppy, to borrow Roy Keane terminology, so far this season. It's not been the best of starts for Trent-Alexander Arnold and Gomez does not always convince.
Coady is something of a throwback – a defender who defends, is positionally astute and does the old school things well. Regardless of the Van Dijk blow, the 27-year-old would be a valuable addition. It would be some story, seven years after he left Anfield.
MIKE KEEGAN
Can Liverpool win the Premier League without Virgil van Dijk?
Yes. Of course they can. But their task is now clearly much more difficult.
Liverpool do not operate with a huge squad and have done relatively well with injuries over the past couple of seasons. The loss of Van Dijk will test them like they have not been tested before and others will have to step up.
Even with the big Dutchman, the defence has not looked as solid as it should - but Klopp is a master of finding a way.
Should Jurgen Klopp look to buy a replacement in January, and if so, who should he go for?
This all depends on who is available.
It's rare that you would find a top class player on the market in January. The fact of the matter is that any club in the world would struggle to replace Van Dijk, especially at a time when there appears to be a lack of central defensive talent in the game.
The arrival of a new man and the disruption and time needed to familiarise that it would bring probably makes it not worthwhile.
JACK GAUGHAN
Can Liverpool win the Premier League without Virgil van Dijk?
Yes, they can win the league because they are that good.
But as Manchester City found last season, losing your best central defender can prove too much to bear without organisation from others.
Nobody stepped up in Aymeric Laporte's absence, with Pep Guardiola regularly forced to chop and change his pairing, and Jurgen Klopp will need both Joe Gomez and Joel Matip to find consistency quickly.
A lot of responsibility rests on the shoulders of Liverpool's sitting midfielder to shield them.
Should Jurgen Klopp look to buy a replacement in January, and if so, who should he go for?
Unless they were planning to sign a centre half next summer then it is probably wise to steer clear of the January window.
That changes if an outstanding loan option becomes available but the odds of a readymade top-class defender being handed to them on a temporary basis seems unlikely.
Clubs will be aware of how desperate Liverpool may be – particularly if the next two months go badly – and overpaying for the sake of five months' worth of football does not seem prudent.
CHRIS WHEELER
Can Liverpool win the Premier League without Virgil van Dijk?
Absolutely.
Van Dijk is a monumental figure for Liverpool, and the single biggest factor in Jurgen Klopp's side making the step up to become English and European champions. But to suggest they can't win the title without him is ridiculous.
The race will be a lot tighter now, no doubt. But this is a very accomplished Liverpool team and one that has consistently shown a willingness to dig deep and fight for each other, becoming arguably greater than the sum of its parts.
To write them off after one injury is foolish.
Should Jurgen Klopp look to buy a replacement in January, and if so, who should he go for?
Yes.
If Liverpool had centre-backs in abundance then it would be silly to panic buy a replacement for Van Dijk. However, they already looked stretched in that department in terms of numbers and quality defenders who can stay fit.
That defensive midfielder Fabinho is already being talked about as a possible replacement does not reflect particularly well on Joel Matip and Joe Gomez, both of whom have struggled for form and fitness.
It makes sense to strengthen in January and sign a new defender who will still be an asset when Van Dijk returns.
KIERAN GILL
Can Liverpool win the Premier League without Virgil van Dijk?
Yes they can win the Premier League without Virgil van Dijk.
Jurgen Klopp just has to roll with the punches and find a solution. Joe Gomez and Joel Matip can still do a job for Liverpool. Another option could be to switch to a back three occasionally. The three can help make up for any defensive deficiencies.
Should Jurgen Klopp look to buy a replacement in January, and if so, who should he go for?
Saying that, Klopp could do with bolstering his back line.
If he's looking for a cut price, rather than splashing the cash, maybe someone such as Lewis Dunk could be a good addition. I rate him highly.
Imagine if they went in for John Stones...
Source: m.allfootballapp.com