The Reds trail 3-0 following the first leg of their Champions League semi-final and, although Klopp's previous bid to overturn that deficit ended in disappointment, he is not deterred from hoping for a different outcome this time.
In April 2014, Klopp's Borussia Dortmund outfit lost 3-0 in the Bernabeu to a Real Madrid side, which included Cristiano Ronaldo, Xabi Alonso, Karim Benzema, Isco and Gareth Bale, in a Champions League quarter-final first leg.
Dortmund threatened to upset the odds in the return fixture and Klopp remains convinced they deserved far more from their 2-0 victory which saw them narrowly miss out.
Many are comparing Tuesday's task to the comeback Liverpool pulled off three years ago against, coincidentally, Dortmund in a Europa League quarter-final at Anfield when they won in added time from 4-2 down on aggregate with 25 minutes remaining.
Klopp, however, has another story about his former club he feels is more relevant ahead of the semi-final second leg.
"I don't think too much about Dortmund. My own personal little story is about Real Madrid, years ago with Dortmund," he said.
"We lost 3-0 there but then at home we changed seven or eight positions and we won 2-0 and we should have won 5-0 without a shadow of a doubt. 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.
"It doesn't mean that it will happen again but it is enough for me to believe. That is what we do, not more."
Klopp, outwardly at least, insists the job against Ernesto Valverde's side is not an insurmountable one even without the injured pair of Mohamed Salah (concussion) and Roberto Firmino (muscle tear).
His team have proved many times this season - they lead the Premier League statistics in terms of winning goals scored in the final 15 minutes - that no cause is ever lost.
"I had these games quite a couple of times," he added.
"In my experience, it's not that before the game you think: 'Yeah, I believe we will do it.' I'm completely fine with the chance. I don't think we have more, but I don't think we have less.
"We believe in the chance, we believe in the opportunity, not in the result.
"A lot of things are possible. It's about how much. Can we believe at the beginning in the opportunity? Then we have to do the right things on the right pitch and then you need a bit of luck, which we didn't have in Barcelona.
"That is clear. We need a little bit more (luck) 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 really 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."
