It would have seemed inconceivable as recently as a few of months ago but when Liverpool and Manchester United meet at Anfield on Sunday, it may be the visitors, not the hosts, who have the best chance of finding weaknesses in their opponent's defence.
Liverpool's recent successes under Jurgen Klopp have been built on sturdy foundations. But they were thrown into crisis when they lost Virgil van Dijk and Joe Gomez to serious knee issues earlier this season and their problems were compounded by an injury to Joel Matip during the recent 1-1 draw with West Brom.
Matip remains a doubt for Sunday's game and if he does miss out, it will be Liverpool's fourth in a row with no senior centre-backs available. They welcome United to Anfield having gone three Premier League games without a win for the first time since May 2018.
Their stuttering form has allowed Ole Gunnar's Solskjaer's side to open up a three-point gap at the top of the Premier League. And while Liverpool's defensive issues have hindered them, United's contrasting form owes a lot to defensive improvement.
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Klopp seeking defensive solution
It is to Jurgen Klopp's immense credit that Liverpool were still top of the Premier League after two months without either Van Dijk or Gomez. But Matip's injury made his job even harder and now it's Manchester United looking down on the rest.
Klopp has tried three different centre-back combinations in the three games since Matip limped off at Anfield last month.
His immediate response against West Brom was to throw on academy graduate Rhys Williams. The 19-year-old featured in all six of Liverpool's Champions League group games this season, either as a substitute or a starter but his appearance against West Brom was only his second in the Premier League.
It's hardly surprising, then, that he had some awkward moments.
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Williams is regarded as an exciting prospect within Liverpool but before this season his only senior experience had come during a brief loan spell with non-league Kidderminster. He has handled the step up impressively but it would be a stretch to expect much more from him in the short term.
Klopp opted for the slightly more experienced Nathaniel Phillips in Liverpool's next game, against Newcastle, and while the Reds kept a clean sheet at St James' Park, the 23-year-old didn't do enough to keep his place in the side against Southampton five days later.
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Instead, Klopp used Jordan Henderson at centre-back. It was not the first time he has played there. In fact, he shone in the position at the Club World Cup last season. But he was partly at fault for Danny Ings' winner at St Mary's and his presence was missed in midfield, where Liverpool were overpowered by the industrious hosts.
Liverpool may yet add another centre-back to their ranks before the end of the January transfer window, but where would they be this season without Fabinho?
The Brazilian has been their only constant in the position in recent months, starting Liverpool's last 11 games in all competitions alongside a series of different partners and serving as the glue holding a makeshift defence together.
His influence can be seen in the statistics. Fabinho ranks top among Liverpool players for tackles, interceptions, clearances, aerials and blocks in the Premier League season. His form has been the most important factor in limiting the damage of their injury crisis.
It's quite an achievement for a central midfielder who had only filled in at centre-back on a handful of occasions before this season, and Liverpool will need him to be at his best again against Manchester United on Sunday - especially if Matip remains sidelined with Van Dijk and Gomez.
Bailly return boosts Man Utd
While Klopp continues searching for defensive solutions, Solskjaer hopes he has found one.
Eric Bailly endured an inauspicious start to the season, marking his long-awaited return to the side with an error-strewn performance in Manchester United's 6-2 thrashing by Tottenham.
But his rustiness in that game was perhaps forgivable given it was his first Premier League start since February - and his first at Old Trafford since April of the previous year. Injury problems have been a persistent theme of the Ivorian's time at United and soon he was sidelined again.
But Bailly has always had the potential to succeed at Old Trafford - in fact, United's win rate is considerably higher in the games he has started in the last five years compared to the ones he hasn't - and he has certainly delivered on that potential since his most recent return to fitness before Christmas.
Between the Carabao Cup win over Everton on December 23 and the Premier League victory over Aston Villa on New Year's Day, Bailly started four consecutive games for the first time since September 2017.
United won three of those games, drawing the other, with Bailly impressing throughout, his standout moment coming against Villa at Old Trafford, when he heroically blocked a goalbound shot from Keinan Davis in the final few seconds to preserve United's 2-1 lead.
It was a vital intervention which earned him the recognition of his team-mates, who mobbed him in celebration after the final whistle, and that of his manager. "His physicality, his pace and his bravery are second to none really," said Solskjaer after the game.
Those qualities have unfortunately worked against Bailly in the past. He has caused himself injuries by throwing himself into challenges other players would avoid. At only 26, his career has already been interrupted by hamstring, shoulder, ankle, knee and thigh problems.
But he shone again in Tuesday's 1-0 win over Burnley, meaning United have kept four clear clean sheets in the six games he has played since his return to action, and his performance at Turf Moor provided further evidence that he is a more suitable partner for Harry Maguire than Victor Lindelof.
That's because as well as being brave, aerially dominant and strong in the challenge, Bailly possesses formidable pace - an attribute United's other central defenders lack. "If he stays fit, he cements his place," said Sky Sports pundit Gary Neville on Tuesday. "Maguire looks more comfortable alongside him with his pace."
It remains to be seen whether Bailly is back for good. His injury history demands caution. But his pace will certainly be useful when Mohamed Salah and Sadio Mane are running at United's defence on Sunday. His presence, in what's now a problem position for Liverpool, might even give the visitors the edge.
Pitch to Post Preview - Liverpool vs Man Utd: Graeme Souness' big match verdict; plus: the likely XIs, injury news, and predictions
In a special Pitch to Post Preview Podcast we look ahead to Sunday's blockbuster between Liverpool and Man Utd at Anfield.
Sky Sports pundit Graeme Souness joins Peter Smith to discuss the big match, including why the hosts will be wary of their rivals and which players must stand up and deliver for their side.
We also get the latest team news and possible starting XIs from Sky Sports News reporters James Cooper and Vinny O'Connor, while football writer Lewis Jones - AKA Jones Knows - makes his Pitch for what will happen in the game.
Watch Liverpool vs Manchester United live on Sky Sports Premier League HD from 4pm on Super Sunday; kick-off is 4.30pm