Between August 2009 and May 2012, a period in which Jürgen Klopp built Borussia Dortmund up and up until they retained successive Bundesliga titles, Mats Hummels missed just seven league games at the heart of his manager’s defence.

Over that same period Neven Subotic was absent for 12 games; the point being that, when it came to selecting his line-up each week, Klopp did not need to worry about his centre-back partnership. It largely picked itself.

Shortly before the end of Monday’s demoralising defeat by Leicester City, the sort of numbing reverse that sparks a debate on just where the club are heading, Liverpool had been exposed as a shambles. A switch to a back three saw their defence consisting of two midfielders in Lucas