One of Anfield's most glorious nights is also up there with the most ignominious in Barcelona's history. 

For the European champions, that famous 4-0 triumph against the Blaugrana was the springboard to a sixth title on the continental stage. 

More than that, it spoke of a superior mentality; a willingness to overcome almost impossible odds and battle until the very end. 

That ethic was - and arguably still is - conspicuously missing from Ernesto Valverde's set-up. 

His side are experiencing their worst start to a season in 25 years. 

The fact they remain top of La Liga is more an indictment of the teams around them than anything else. 

There are several possible reasons for their decline, which has seen them suffer three defeats already in 2019/20, most recently a 3-1 reverse away to Levante.

However, the Spanish press are unanimous on the heart of the problem. They believe Barcelona's issues are psychological, and they date back to Anfield. 

SportWitness have compiled a number of reports from the likes of AS and Mundo Deportivo, all coming to that same conclusion. 

It's even claimed Barcelona are suffering from "post-traumatic stress" due to their humiliation on Merseyside.

After all, they were all but through following the first leg. Then Divock Origi and Gini Wijnaldum both scored a brace apiece, and Barcelona failed to reply. 

Mundo Deportivo's report suggests even new players like Griezmann are being affected by the memories of that night, such is the negative culture permeating Camp Nou in the wake of another Champions League disappointment.

That would go some way towards explaining why many - with the exception of Frankie de Jong, who suffered his own semi-final heartache against Tottenham as an Ajax player - are struggling to make an impact. 

It is a "wound that continues to bleed" and is becoming known, at least in AS, as "Anfield syndrome" - particularly when it comes to away games.

Barcelona's record on the road is especially underwhelming, losing two and drawing two in all competitions already this term.

Valverde has countless challenges ahead of him.

Probably the biggest of all is putting back together a dressing room who are still reeling from a game which happened almost five months ago.