It is in these situations, when the odds seem insurmountable, that Anfield looks to its past for inspiration and seeks reassurance that all is not lost.
Whenever Liverpool return home with a deficit to retrieve, nights with Saint Etienne, Auxerre, Chelsea, AC Milan and Borussia Dortmund are recalled but those who submerge themselves in history ahead of Barcelona’s visit will not find Jurgen Klopp doing likewise.
Liverpool’s manager was central to one of those dramas, the Europa League quarter-final against his old club in April 2016, but that match will not feature in the narrative he presents before kick-off to his players. The name of Dortmund, however, will be central to the plot.
Jurgen Klopp’s Liverpool are 3-0 behind ahead of second leg against Barcelona on Tuesday
In April 2014, Klopp found himself in a similar position. Dortmund lost the first leg of their quarter-final with Real Madrid 3-0 and nobody gave them a chance, similar to the way people are viewing Liverpool’s task of overhauling Barcelona.
The task, ultimately, proved beyond Dortmund but they won 2-0 after Klopp made a number of unexpected tactical decisions, switching from 4-3-3 to 4-1-4-1, and bringing in players who had been on the periphery. The element of surprise was so nearly their making.
‘We should have won 5-0, without a shadow of a doubt,’ Klopp said. ‘We were clearly the better side – but it was Madrid then and it’s Barcelona now. It’s a big difference. I don’t want to talk too much, but I have told the players that story.
In 2014 Klopp found himself in a similar position against Real Madrid at Borussia Dortmund
‘We changed the team on purpose, more or less. Oliver Kirch was a really good player, who had only played a couple of games, but that was the eye-opener for the whole world.
‘Everyone was thinking, “Who’s that guy?” He played an unbelievable game that night against Madrid.
‘It doesn’t mean that it will happen again but it is enough for me to believe. That is what we do, no more. I understand all these questions about the past but a lot of things are possible.
‘It’s about how much we can do. Can we believe at the beginning in the opportunity? We will see.’
Klopp would not entertain any line of questioning that involved Liverpool making flying starts or adding Barcelona to their famous list of conquests — ‘I do that then Ernesto Valverde translates the headline into Spanish and shows it to his players,’ he said — and his mood was sanguine.
Liverpool were without a number of key names in training ahead of their clash with Barcelona
Trent Alexander-Arnold plays a pass during a possession-based drill in training on Monday
Barcelona have been unbeatable in the Champions League this season and Klopp is realistic about what Liverpool might achieve especially as he will be without injured strikers Mohamed Salah and Roberto Firmino, but there is still that grain of optimism and the stadium would ignite if the hosts plunder an early goal.
‘We have to do the right things on the pitch and then you need a bit of luck, which we didn’t have in Barcelona,’ said Klopp, whose team were well in the contest until Lionel Messi took control six days ago. ‘That is clear. We need a little bit more at home. Then we need a fantastic atmosphere.
‘We have two of the best strikers in the world not involved, so of course we need the crowd involved. Some things will be new, 100 per cent, with not any time to train.
‘That’s how it is but I am still looking forward to it. It’s all good. It’s the Champions League and you want to be a part of it.
‘We were so happy when we came through the quarter-final and now we are in the semi and we have to use the second leg. It gives us a basis we can work with. If it’s possible there, then it’s possible here.’
Sadio Mane closes down Rhian Brewster as he tries to get the ball off the English youngster
Divock Origi pips Fabinho to the ball as Daniel Sturridge watches on during the session
The big question, however, is whether Klopp and his players believe they can do it. They have put such effort into this campaign that you wonder how mentally drained they are and an early Barcelona goal on the counter-attack would put a pin in the atmosphere. Nonetheless, hope remains.
While there is hope, Klopp will implore them to make their own story. The club’s past will not help them negotiate the threat of the world’s greatest player and his team-mates but Barcelona are not infallible and Liverpool are not prepared to surrender.
‘In my experience, it’s not before the game that you think, ‘Yeah, I believe we will do it’ but I’m completely fine with the chance,’ said Klopp, who will gave a late test to Virgil van Dijk after he trained alone at Melwood on Monday.
‘I don’t think we have more of a chance, but I don’t think we have less. We have at least a chance. They are halfway through.
‘That’s the truth, but as long as it’s not decided that’s the competition. You have to try and we want to try.
‘That’s all I can say about it. I don’t sit at home and tell my missus wait for me at home, we will have a party after the game because we’ll win it. We have to work for it. That’s why I think it’s worth it.’
Dejan Lovren and Xherdan Shaqiri stretch as they warm up their muscles before training
Daniel Sturridge may have a huge role to play at home against Ernesto Valverde’s side