Liverpool have had a dramatic drop off in form and Vinny Perth joined OTBAM on Tuesday to provide a tactical analysis of the Premier League champions.

Perth studied the core tenets of Liverpool's game, what made them successful last year and what has gone wrong during the current season.

While Jurgen Klopp's men have undoubtedly dealt with numerous injury problems this year, much of the issues they have faced have been through tactical changes from last year to now.

In some instances, Klopp's hand has been forced in making alterations to the team.

Like many top clubs, much of Liverpool's strength came from an ability to squeeze the game into the opposition half.

That usually stemmed from the strength and bravery of Virgil van Dijk and Joe Gomez who orchestrated Liverpool's high line.

Liverpool's Virgil van Dijk (right) is challenged by Everton goalkeeper Jordan Pickford during the Premier League match at Goodison Park, Liverpool.

"When van Dijk and Gomez are in the team they squeeze the pitch and the life out of the opposition," Perth said.

"It is very, very brave of the team."

The knock-on effect of not having van Dijk and Gomez available has shuddered throughout the team and forced Klopp to deplete arguably the greatest collective asset that Liverpool have; the dynamism of the midfield.

"All of the plaudits for pressing started with the front three and they are world-class at it," Perth admitted

However, while Mohamed Salah, Roberto Firmino and Sadio Mane rightly received praise, the three players behind them were fundamental to the team's success.

"The three players behind them [Jordan Henderson, Fabinho and Georginio Wijnaldum] were instrumental to how Liverpool played."

Their ability to squeeze opposing teams into the final third of the pitch "was really crucial to how Liverpool played last year and to how they became one of the best teams in the Premier League, of all time, as a result of it."

While Perth is a fan of Thiago's signing, there is no doubt that there is a drop off in running power in Liverpool's engine room when he and Curtis Jones play together.

Liverpool's Curtis Jones during the UEFA Champions League Group D match at Anfield, Liverpool.

"Liverpool do not have that intensity, that running power [with Jones and Thiago] that the other three provide," Perth said.

"When you take 66 per cent out of your midfield three the fall off for Liverpool has been colossal."

That has hindered the effectiveness of the Liverpool forwards, according to Perth

Liverpool's inability to press as a collective, sparked by the midfield, has created additional work off the ball for Salah, Firmino and Mane which has taken its toll during the course of the year.

"What is starting to happen is they have lost the will to press because of what is happening behind them."

Firmino's own altered role within the teams defensive unit has also aggravated this.

Aston Villa's Ollie Watkins and Liverpool's Roberto Firmino (left) during the Premier League match at Villa Park, Birmingham.

The Brazilian has regularly been forced to drop onto the opposing teams' deep-lying midfielder instead of pressing right up to the centre-half.

Last year, Firmino did this to excellent effect forcing mistakes and turnovers that led to chance creation.

"Strikers, no matter who they are, do not want to be running for too long," Perth said.

"They want the ball, they want to be scoring goals. Their patience has worn thin a little bit and the amount of running they are doing has dipped."

It is clear that Liverpool's struggles have been caused by personnel changes as well as tactical ones. Their poor form has been caused by a myriad of reasons and cannot be pinned on one thing in particular.

Klopp may be forced to address some of the above tactical nuances if his side are to prevail in the Champions League and haul back their rivals for a place in the top four of the Premier League.

Watch the full tactical breakdown of Liverpool by former Dundalk manager, Vinny Perth above.

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