Liverpool's recent back-to-back draws away from home against Arsenal and Manchester City told us plenty about the character of the side, the promising development of several players and how the club is gradually moving in the right direction under Brendan Rodgers leadership, but the one remaining bugbear I have is the myth that the club currently boast one of the best defences in the league, if not Europe, starting with their failing central partnership of Daniel Agger and Martin Skrtel.

The Slovakian didn't start against either City or Arsene Wenger's side, with Jamie Carragher brought into the side to add some steel to proceedings, but that's more a stinging indictment of their lack of form, both as a pairing and individually than anything given his recent decision to retire from professional football at the end of the season. The Slovakian international hardly covered himself in glory during the defeat to Oldham and he will now have to work his way back into the side. The 35-year-old vice-captain's achievements in the game, though, are all the more remarkable given that he was never the tallest or quickest central defender with the best technique, but now more than ever before, his ability to organise a back four is without peer around Anfield.

Edin Dzeko's goal at the Etihad Stadium came after Agger rocked back on his heels, anticipating the space that the striker would attack, before losing his man and seeing the ball drift past him and leaving a simple tap-in. It was similar to the goal Arsenal scored through Olivier Giroud at the Emirates, with the Denmark international caught on his heels and leaving the Frenchman to steel that crucial yard and get a leap on his marker before nodding home and handing his side a lifeline which they grabbed with both hands. To add to that list, the early lead Robin van Persie handed Manchester United in the 2-1 defeat at Old Trafford came from a very similar fault and a concerning pattern has emerged.

Agger has always been a neutrals favourite simply because he can pass the ball well and everyone likes a ball-playing centre-half; they look good both on and off the ball. Terms such as 'cultured' and 'Rolls Royce' are trotted out, but only really Rio Ferdinand has lived up to such a high standard in the last decade in the Premier League on a consistent basis. Fine footballer though he may be, Agger has always had a game-changing error in him and a loose grasp on the concentration levels required to be a top centre-back.

Skrtel on the other hand is a natural defender who appears to thrive on putting his head in where it hurts and basically kicking people for fun. This had led to a dangerous penchant for giving away needless fouls in silly positions and inviting pressure from the opposition, which with the aerial ability of the side in general in question this campaign, is tantamount to gross incompetence, while he has always worked best with a leader beside him; a vocal presence like Carragher and he looks a little lost without his team-mate at times, both positionally and mentally.

He's not the ball-player like Agger is, but they are supposed to compliment one another well and certainly last season under Kenny Dalglish they did just that, but this season they've seriously struggled and routinely disappointed. They are both captains of their respective country's international teams, Slovakia and Denmark, and as such, they should not be wilting under pressure in the manner they have been this term.

With Carragher retiring, Sebastian Coates' terrible display in the FA Cup defeat away at Oldham just further highlighted the dearth of defensive talent at the club. The Uruguayan simply can't be trusted at the moment and would seriously benefit from a loan move away, preferrably in the top flight, as was Rodgers intention during January if he could find a suitable replacement, hence the tentative interest in Southampton's Vegard Forren at the beginning of the window.

Having kept  a respectable total of nine clean sheets in the league so far does not quite tell the full story. The team's ordinary away record has seen them leak 22 goals and win just three games on the road, the worst record on both counts in the top eight and one of the main reasons they remain short of the top four. Having conceded 40 league goals all last season, they look well on course to better that with 32 already being scored against them, even if they look capable of equalling last year's tally of 12 clean sheets despite the clear stagnation of the back four, with Martin Kelly worthy of serious consideration as a potential option given Wisdom's lack of height for the central role looking further ahead.

Given that the idea of selling Agger to City was toyed with in the summer and Zenit St Petersburg's recent interest in Skrtel, it would be a surprise not see Rodgers move for a serious contender to challenge them both in the summer if they are kept around, which would be the best course of action. The complete collapse of Pepe Reina's form over the last two years or so just further adds another potential headache into the mix and major surgery could be required at the end of the season, but neither should be consigned to the scrapheap just yet even if the same cannot be said for the man between the sticks.

We were told that Skrtel's errant back-pass to allow Carlos Tevez to pinch an undeserved equaliser in the club's 2-2 draw at Anfield to the reigning champions at the beginning of the season was a symptom of the pair adjusting to Rodgers methods, style of play and vision for the future, with a firm commitment to passing football the order of the hour, but fast forward seven months and the errors are just as prevalent and show no signs of disappearing any time soon.

Rodgers wants his centre-backs to split, with the holding man, usually Lucas Leiva in this case, to drop between them when they are in possession high up the pitch, encouraging the full-backs to push on. To their credit, Glen Johnson, Jose Enrique and Andre Wisdom have all done very well this season, but the damage and impact this shift is having on those inside of them is hard to ignore, despite the lack of attention their drop in form has been given.

On paper, the Skrtel and Agger axis looks a balanced partnership, which given their age should be set to form the basis of the team for years to come but faith in them as a duo is on the wane. There is little evidence to suggest that both are capable of adjusting to what Rodgers wants and with the jury out on Coates and Carragher's retirement imminent, the most overrated defensive pairing in the top flight, claiming the title from Thomas Vermaelen and Laurent Koscielny at Arsenal, may need breaking up if the side are to progress. A lack of competition may be partly to blame and time is on their side still, but such underperformance over such a prolonged period simply can't go ignored and a solution must be found in the future.