The injury to Virgil van Dijk means that Liverpool are without the greatest defender ever to play the game.
That's the opinion of Danny Murphy, whose controversial comment sparked a hot debate on social media.
It got us thinking about who really is the greatest centre-back ever to grace the game.
While Van Dijk's impact on Liverpool is unquestionable, he doesn't get the nod when we asked our top writers who they would pick.
So, who is the greatest of them all?
Jeremy Cross - Franco Baresi
The Italian centre back was a Rolls Royce of a centre back, who spent his entire club career at AC Milan to help them win three European Cups and six Serie A titles.
Baresi also won more than 80 international caps and was a key member of the Italian side that won the 1982 World Cup.
Baresi rarely made a mistake and always seemed to have so much time on the ball, which is always the mark of a world class footballer.
Paul Brown - Franco Baresi
Off the top of my head I can think of a handful of defenders currently still far "greater" than Virgil Van Dijk, including Franz Beckenbauer, Bobby Moore, Gaetano Scirea, Paolo Maldini, and if we're talking Premier League, John Terry too if only for his immense leadership qualities.
Van Dijk just doesn't have the body of work to come close to any of them - yet.
But in my lifetime the greatest I've ever seen was Franco Baresi. Romario is still having nightmares about what Baresi did to him in the World Cup final in 1994.
People forget, Baresi shouldn't even have played. He'd just had knee surgery and missed most of the tournament.
But he came back for the final and gave the most immaculate defensive performance I have ever seen on a football pitch. In searing heat. At 34 years old. Baresi was as close to perfection as it's possible to be.
Always a step ahead. Always in the right place. Every tackle and interception made to look easy. And he glided around the pitch playing clever little passes and setting Italy on their way all the time too.
Never been more upset to see someone miss a penalty.
Aaron Flanagan - Fabio Cannavaro
The ultimate defender during my childhood and teenage years. Not the big, towering centre-half type that Virgil van Dijk is, but he makes up for it with immense quality.
He was a winner wherever he went - and even took that into individual accolades, becoming the only-ever defender to be named FIFA World Player of the Year in 2006. He scooped the Ballon d'Or that year, too.
Without question, Italy would not have won the World Cup if it was not for his presence - and he had a similar influence on Real Madrid and Juventus.
The only travesty has to be that he was stripped of his two Serie A titles in the match fixing scandal.
Joshua Peck - Jaap Stam
I’m not old enough to have seen the likes of Beckenbauer, Moore, or even Koeman, so am going to steer clear of that trio.
Instead, I’m going to go with one of Van Dijk’s fellow Dutchmen in Jaap Stam.
I still get scared looking at the former Manchester United man - he was so strong and had the pace to match too.
That Sir Alex Ferguson admits letting Stam go was one of his biggest mistakes tells you everything.
Ollie Salt - Franz Beckenbauer
He may have plied his trade before my time, but it’s hard to make a case against Beckenbauer being the GOAT when it comes to centre-backs.
For a start, Der Kaiser is the only defender to have lifted the Ballon d’Or on two occasions and one of just three who have claimed the prize in its history.
He also captained West Germany to the 1974 World Cup and won three consecutive European Cups for Bayern Munich, with whom he made 584 appearances. Not many centre-backs have come close to achieving what Beckenbauer did in his iconic 20-year career.
Jack Staplehurst - Bobby Moore
It’s tough to compare players of different generations, so looking at what makes someone a true icon of the game is the best bet.
West Ham and England legend Moore remains the only Three Lions captain to lift the World Cup.
And the way he is remembered even today shows few have ever reached his level. A dream leader on and off the field.
Matt Maltby - John Terry
If we're talking solely about performances on the pitch, it's got to be the Chelsea defender.
Terry was the ultimate English centre-back during his heyday; tough-tackling, dominant and a leader.
You know you'd always get 100 per cent from him and rarely did he put a foot wrong.
Like Van Dijk, he won everything during his glittering club career with Chelsea - and it's no understatement to say Chelsea would have won less had they not had Terry in defence.
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Mark Taylor - Franz Beckenbauer
Despite having never been able to watch him live, German legend Franz Beckenbauer is the answer that immediately springs to mind.
A born leader like all good centre-backs should be, Beckenbauer could easily have won three World Cups, and he also dominated club football with Bayern Munich.
He could play practically anywhere on the pitch, and let’s not forget he invented the sweeper role too!
Warren Muggleton - Franco Baresi
One of the reasons van Dijk is revered in world football is his ability to act as the stopper on opposition attack as well as the initiator of Liverpool’s moves.
It is the style of defence that is now demanded across Europe’s top leagues – but it all came from AC Milan’s Player of the Century.
Making more than 700 appearances over 20 seasons, it saw Baresi win six Serie A titles and three Champions Leagues at the San Siro.
More importantly, his aggressive defending and ability to play out from the back set the new norm over the 1980s and 1990s.
While the Italian has recognised van Dijk’s skills, calling him the “best defender in the world” last December, it feels like the sorcerer commenting on the apprentice.