Premier League 2018-19: Alberto Moreno remains Liverpool's biggest unsolved weakness

Liverpool have come a long way since the appointment of Jurgen Klopp. As a mark of the progress made by the club under Klopp, Liverpool have reached three finals, although they lost all three.

They have gone from signing the likes of Allen and Borini under Rodgers to making world-class recruitments like Alisson and Van Dijk.

Liverpool on their day are possibly the best attacking unit in the world, and their free-flowing football is winning hearts all over the world. On top of that, they have the highest scoring trio of the last season spearheading their attack - namely Mane, Salah and Firmino.

Even their one Achilles' heel from the past - their defense - looks stronger than ever before. Liverpool's first choice XI is arguably second only to that of Manchester City in the Premier League.

But despite all the world-class players available to them, there is still something that's hurting Liverpool.

There's a saying that a team is only as strong as its weakest link. But what is Liverpool's weakest link? The answer, which most Liverpool fans will agree with, is Alberto Moreno.

Although not a regular starter anymore, Moreno's odd appearances still show the need to sign another backup for Robertson. Liverpool got knocked out of the League Cup in the first round against Chelsea, conceding twice.

Remarkably, both the goals came from the left side - and this was Moreno's first start of the season. In both goals, Moreno was unable to close the player quickly enough, and he couldn't land a good tackle either.

In Moreno's first Premier League start of the season and his second of the season, against Cardiff at home, Liverpool conceded their first goal at home after going nine consecutive Premier League games without conceding. Again, the cross came from the left side where Moreno was unable to close down or get in a good tackle.

His poor performances on the big occasions, like the Europa League final in 2016, show that he is a misfit in a team of Liverpool's stature. And Klopp's decision to use a centre midfielder as a makeshift left-back for the whole season reinforces his lack of belief in Moreno's defensive abilities.

Although defensively vulnerable, Moreno is quite good in going forward and supporting the attack. But that's not what the team needs right now.

With Moreno's contract ending at the end of the season, it looks highly unlikely that Liverpool will offer him a new one. Klopp can then get the backup option sorted for good.