Clearly, Liverpool's season has been ruined by a number of long-term injuries. 

While they could still make an unlikely run at Champions League qualification for next season, 2021 saw their otherwise fairly promising title defence crumble into crisis and, although there have been mitigating factors, a number of their players have struggled to convince. 

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Though the injuries to Joe Gomez and Virgil van Dijk (among others) have to be taken into account, some of Jurgen Klopp's key players haven't looked the same since winning the Premier League. 

With that in mind, GIVEMESPORT writers Jonathan Gorrie, Christy Malyan, Joshua Cole and Sam Brookes have shared their opinions on exactly who has let the Merseyside giants down the most this season. 

*All stats correct prior to this week's football*

Jonathan Gorrie 

Sadly, it's got to be Trent Alexander-Arnold. 

Few would doubt his quality and the 22-year-old is clearly still learning though his dip in form this season has been alarming. Indeed, his averages for key passes (2.3 to 2, via WhoScored), long balls (5.1 to 4.5) and crosses (2.1 to 1.6) per game have all taken hits. 

When also taking into account the huge drop in assists (13 to 5), his overall game has been really rather poor for too much of the season. 

Given the England international has rarely been noted for his defensive work, the fact his attacking output has severely dropped renders the option to have a player of such passing quality really rather pointless. 

At his best, Alexander-Arnold is a creative force capable of covering up Liverpool's lack of guile in central areas but, at his worst, he's a defensive liability, as Gary Neville alluded to on Sky Sports last month.  

Joshua Cole

“Whilst it is safe to say that Klopp has managed to pull off some masterstrokes when it comes to transfers during his time in charge of Liverpool, signing Thiago has turned out to be a major error.

“Despite playing an integral part in Bayern Munich’s Champions League success last season by featuring in 10 of their 11 games in the competition, the Spain international has ultimately failed to adjust to life in the English top-flight.

“Although he has not been helped by the absence of Jordan Henderson and Fabinho who have both had to cover at centre-back this season, Thiago has only managed to provide one direct goal contribution in 26 appearances which is a dismal tally for a player of his ability.

“In order to win over the club’s supporters, the former Barcelona man will need to step up his performance levels next season to help the Reds launch a push for the Premier League title.”

Christy Malyan 

"I've always viewed Sadio Mane as the most reliable element in Liverpool's attack. Mohamed Salah's involvement in games can fluctuate between astonishing and anonymous, while Roberto Firmino's overall contributions have been in steady decline for some time now.

"Mane, though, has always provided a level of consistency, an assurance of what you can expect from him - relentless running, threat in behind and the creation of chances, whether for himself or others, with solid regularity. He's got strikers' instincts, but he's generally a lot less selfish than Salah which, for me, makes him perhaps the most functional player in Jurgen Klopp's system. He simply performs his role to near perfection.

"Bearing that in mind, this should have really been the season where he's stood out most in Liverpool's starting XI while the rest of it has struggled for varying reasons, carrying the torch and helping maintain standards during a very difficult chapter in Klopp's Anfield history.

"In the early part of the season, that was certainly the case with five goal involvements in his first five games. But towards the turn of the year his form suddenly plummeted and from there, the Senegal forward just hasn't recovered. He looks bereft of confidence, his touch has become incredibly sloppy and that industriousness in his game has waned as well.

"There's been a handful of goals and assists more recently, but Mane's all-round play seems to be so far off what we've come to expect and from a player who's been so reliable ever since moving to Anfield, it's bizarrely out-of-character."

Sam Brookes

"Roberto Firmino has been bitterly disappointing.

"While his game has never been based around the number of goals that he scores, his return in front goal has been very poor this season. He has managed just six goals in the Premier League, and has looked very low on confidence.

"The argument has always been that he offers the team so much more, though, than just goals.

"However, that has not been the case in 2020/21. It's been a joke. 

"He has produced fewer key passes than Trent Alexander-Arnold, Andrew Robertson, Mohamed Salah and Sadio Mane. At times, he has been a passenger in games, appearing to be a step or two behind his teammates.

"When Liverpool suffered injuries to their defence in the early part of the season, it was clear that their attack was going to have to step up. Unfortunately for them, Firmino has not risen to the challenge at all."