Here the PA news agency takes a look at the issues facing Liverpool's established names – and the potential solutions.

Fabinho

The Brazil midfielder has slotted into centre-back in place of the injured Virgil Van Dijk seamlessly but a minor muscle problem looks set to sideline him for the next couple of matches.

Joel Matip

Matip is likely to be out for several weeks with ankle ligament damage sustained in the win over Tottenham, in which he was replaced at half-time. The defender has been plagued by injuries during his time at Anfield, struggling to string together a run of appearances, and this latest setback is the push Klopp needs to bring in another centre-back.

Virgil Van Dijk

Liverpool have always been reluctant to rule out Van Dijk for the season despite an ACL injury sustained in October but the next week could be indictive of his recovery when the club have to re-submit their Premier League squads for the remainder of the campaign. The Holland captain was omitted from the 25 for the first half of the season as there was no chance of him featuring but if he makes the cut this time it will be a sign the club think he can return before the conclusion.

Joe Gomez

Gomez had surgery in November on a knee tendon injury sustained on England duty and so is slightly behind Van Dijk in his rehabilitation. Like his fellow defender, Liverpool have not ruled out his participation again this season but that seems unlikely.

Jordan Henderson

Liverpool's captain became the second midfielder pressed into action at centre-back because of injuries. The England international has played three Premier League matches in defence, conceding two goals, and is likely to continue that at West Ham on Sunday.

Rhys Williams

The 19-year-old Williams had done well as a temporary stop-gap and featured in all six Champions League group stage fixtures. He was unfairly singled out for criticism for a mistake in last weekend's FA Cup defeat to Manchester United, considering a year ago he was on loan at Kidderminster Harriers.

Nat Phillips

Phillips gained experience playing on loan for Bundesliga 2 club Stuttgart last season and has made only five appearances for Liverpool, the latest being Matip's replacement at Tottenham in midweek. That would appear to put him in pole position to fill the current void.