Former Liverpool goalkeeper Chris Kirkland has urged Jurgen Klopp to stop rotating his shot-stoppers.
Loris Karius is expected to start when Liverpool take on Sevilla on Wednesday, despite being left on the bench for Saturday's 5-0 league thumping at Manchester City.
And Kirkland told the Liverpool Echo: “For me the No.1 goalkeeper should play in both the Premier League and the Champions League. You want your best keeper playing in those two competitions.
“I've always been brought up on the idea that your goalkeeper and back four stay more or less the same. You need that unit.
“I've been lucky enough to play behind some very good centre back partnerships – at Liverpool it was Sami Hyypia and Stephane Henchoz, and you knew what you were getting from them.
“At the minute Liverpool don't have that. The defence is not settled, and that is not helpful. It needs addressing."
On Simon Mignolet having to make way for Karius, Kirkland added: “It will definitely affect Simon. Being left out against Arsenal will have affected him.
“For me, that's not ideal going forward. You want to know, you want to be settled."