It might not have been him directly making the mistake but not following his man or being in the wrong position could have attributed to a goal conceded. Something that is less obvious than something like Allison’s drop but that klopp will see and know can be worked on.
I have time today . I have watched all our league games and to my re collection Chelsea - Came on when we were 1 down Arsenal - Didn't play Cardiff - Didn't play Burnley - Corner conceded nothing to do with him United - Goal from right side plus Alisson error Tottenham - Was off during the time Lamela scored Leicester - Came on after Alisson's blooper In principle he can defend better but can't say he is responsible for any of the goals we have conceded even in earlier phases of play.
I would say go back to very early part of season. look at league cup where we lost to Chelsea wasn't it? before his injury.