Jurgen Klopp asked to sign a centre-back in January.
Defensive duo Virgil Van Dijk and Joe Gomez are long-term absentees and Joel Matip recently picked up a knock last week.
Fabinho has been used as a makeshift centre-back and academy players Rhys Williams and Nathaniel Philipps are being called upon.
John Aldrige wants the club to sign a centre-back in the January transfer window.
“Word has been coming out of Anfield suggesting Liverpool are not looking to sign anyone next month, but it has to be a smokescreen because they simply have to sign a centre-half if they are serious about retaining the Premier League title,” he told Sunday World.
“Joel Matip’s injury in Sunday’s 1-1 draw against West Bromwich Albion confirmed what we have all appreciated for some time now – Liverpool have to spend money on a good quality defender.
“I like Matip, and if he could be relied upon to play the majority of games in the second half of the season, manager Jurgen Klopp might be able to get through to next summer with the current squad.
“Yet, the reality facing Liverpool heading into Wednesday’s game at Newcastle is pretty stark – they have one senior centre-back to call upon and he is a midfielder, Fabinho.
“The injuries to Virgil van Dijk and Joe Gomez have ripped a hole in Liverpool’s defensive line and with Matip clearly struggling with his fitness, Liverpool are horribly short at the centre of their defence.”