Liverpool manager Jurgen Klopp may sign a second central defender after sealing a £2m deal for Preston's Ben Davies, with Marseille's Duje Caleta-Car and Schalke's Ozan Kabak potential targets.
The Reds are exploring a number of options as they wrestle with a defensive injury crisis.
Joel Matip has joined Virgil van Dijk and Joe Gomez on the injury list.
Fabinho, who has deputised in defence, was also absent for Sunday's 3-1 win at West Ham.
One added bit of intrigue to Liverpool's interest in 20-year-old Turkey international Kabak is that the success of it may yet depend on whether Schalke sign a replacement. They are being strongly linked with Arsenal's Shkodran Mustafi, who has also figured in Liverpool's discussions.
Klopp named his 12th different centre-half partnership in 21 league games for the game at London Stadium, with Jordan Henderson alongside Nathaniel Phillips.
The capture of Davies, 25, is expected to be completed following a medical and Liverpool are delighted to add him since Celtic were convinced they had secured him on a pre-contract agreement.
The left-sided defender came through Preston's youth system and has had spells on loan with York, Southport and Newport. He is expected to have a medical with Liverpool on Monday.
Burnley were also interested but it is understood Preston were not keen to sell to a local rival.
Bournemouth were considering a bid as part of a double deal also including Ben Pearson, while Sheffield United were also in the mix - but Davies jumped at the chance to move to the Premier League champions.
The Reds will pay £500,000 up front with add-ons worth up to £1.1m relating to first-team appearances and any other achievements he contributes to, as well as any England honours he may win.
It is also believed there is a sell-on clause for Preston if Liverpool make any profit on a future deal for Davies.
Liverpool's 19-year-old Dutch defender Sepp van den Berg is expected to join Preston on loan as part of the deal.
Who is Ben Davies? 'A real steady Eddie'
Former Preston and Liverpool defender Mark Lawrenson
Ben Davies has done well at Preston and has let his contract run down so he was going to move on in the summer. If he'd gone to Celtic, which I'd heard had been agreed, then I was thinking he could do well there, but being honest I didn't really see him as being good enough to be on Liverpool's radar.
He's a real steady Eddie. He's left-footed and quick enough but he's not got phenomenal pace or anything like that.
He's been good in the Championship, very good.
But I've watched him and thought, up against the extra nous and quality you get in the Premier League, on top of extra pace, it will be a test for him. You wouldn't want to just throw him in to face Manchester City next Sunday, put it that way.
This is obviously a great move for him, I just can't see him getting near the first team. Nat Phillips has done well when he's come in and he is probably a better player.
So, Davies would be behind him and also Rhys Williams, so even before Joel Matip comes back and the other two long-term injured players - Virgil van Dijk and Joe Gomez - he is going to be below them on the list. And Fabinho and Jordan Henderson too.
I am not sure he will play very much at Liverpool, but the experience alone should be fabulous. I hope he experiences playing in the first team, but even if he is just sitting on the bench then it is still great for him.
He has come through the ranks at Preston, learned his trade with loan spells in the lower divisions and improved a lot. He has done really well.
Regardless of whether he gets a chance or not, it is a great move for him and Ben is a lovely lad. I've got to know him over the years and with people like that, you just think 'great opportunity and good luck to you'.
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