Jurgen Klopp has indicated both Nat Phillips and Rhys Williams will be needed next season as doubts continue over the fitness of Liverpool's injured centre-backs.
Phillips and Williams have emerged as key players in the battle for Champions League qualification with on-loan Ozan Kabak and fellow February signing Ben Davies having joined long-term central defensive absentees Virgil van Dijk, Joe Gomez and Joel Matip in the treatment room.
Van Dijk confirmed on Wednesday he will miss Euro 2020 as he concentrates on his rehabilitation from surgery after suffering knee ligament damage in October.
Gomez, out since November with a knee problem, and Matip, sidelined in January by an ankle ligaments issue, have started running outside at Liverpool's training complex at Kirkby.
But with no guarantee the trio will be available for the start of pre-season, Klopp is expecting to retain Phillips and Williams, who impressed in Thursday's 4-2 win at Manchester United.
"I've said before, it's not sure that the three centre-backs who are injured will start the pre-season with us," said the Reds boss.
"The boys (Phillips and Williams) will be here. We need the numbers of centre-halves, we need to work on all the different things and step by step we hopefully have the other guys back.
"The boys did incredibly well. Ozan came in and played a super part for us, but is now injured.
"Nat now for weeks already, Rhys at the start, mainly in the Champions League because Nat wasn't on the list for the competition and we had to figure out how we can make sure at least one of the two can play.
"Now they are playing together. They did really well at United, I loved what they did.
"This year they have created two proper careers. When you are at the Academy at whichever club, that's not written in stone, but now they have could show how good they are. Everything will be fine."
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Liverpool are nevertheless planning to bolster their defensive resources this summer having drawn up a five-man centre-back shortlist.
Among the main targets is 21-year-old RB Leipzig centre-back Ibrahima Konate - who has a confirmed release clause believed to be in the region of £34million - while the Reds have yet to make a decision over whether to trigger an option to make Kabak's move from Schalke permanent for £18m.
With Kabak still struggling to overcome a muscle complaint, Phillips and Williams are in line to start together for the third successive game at West Bromwich Albion on Sunday afternoon, where a Liverpool victory will move them to within a point of the top four.
"Team selection is based on performance and training," added Klopp. "The door is always open. I don't get blind that I don't see a good performance anymore.
"In general, the concentration level they (Phillips and Williams) showed at United was immense. Absolutely insane what they did there against the front four of United. It's not easy, but it was really well supported by our two full-backs.
"They were really leading the line with a lot of talks. Rhys is a natural talker on the pitch, which helps. I liked how we organised the last line, that was really good."