So often watertight, the Reds' rearguard has been leaking goals at an alarming rate compared to the typically miserly standards set throughout much of Rafael Benitez's tenure.
Take the league alone. With only two defeats last season, Liverpool conceded just 27 goals; an average of 0.71 per game.
The fact the Reds are two thirds of the way to equalling that tally already is cause for concern.
Eighteen goals shipped in the first 12 Premier League games this time around has taken the ratio up substantially to more than double at 1.5 goals conceded per match.
Last season it took until February 22 and the 1-1 draw with Manchester City at Anfield for Liverpool to concede that amount on the way to claiming the third best defensive record in the league behind Chelsea and Manchester United.
Only Sunderland (19) and, wait for it, Burnley (25) currently have worse records of the teams in the top half of the table.
It is a worrying statistic and one, says Emiliano Insua, that needs to be addressed if Liverpool are to start climbing the table.
'I'm not sure why our record hasn't been as good this season,' Insua said.
'Maybe it's partly down to concentration? But it is also clear that we are conceding too many goals from set-pieces.
'We know we have to improve in this area. The players and the staff have to work to try and find a solution.'
Liverpool's frailties at set-pieces is something Albert Riera alluded to in this week's ECHO when he said: 'We have conceded a lot of goals from free-kicks. You didn't see that last year and we are the same players.'
While it was difficult to legislate for Cameron Jerome's stunning strike to put Birmingham 2-1 up last Monday night, the ease with which the ball found Christian Benitez for the equaliser highlighted what has become an Achilles heel for the Reds defence this season.
'We have to work harder at defending set-pieces,' insists Insua.
'We've conceded too many goals from set-plays. The only way we can change that is by working harder and try to do the same as we did last season, when our defensive record was very good.'