Long before a heart-breaking Champions League defeat against Madrid, Klopp first met the Spanish giants during the 2012/13 season, and announced himself to the world.
Already the next big thing in management with back-to-back Bundesliga titles coaching Borussia Dortmund, the German tried to go one further the following year, and almost made it.
An Arjen Robben winner in the final of the 2013 European Cup ended one of sport's great fairy tales as Bayern Munich edged an all-German affair at Wembley, but Klopp's status was already confirmed.
Four Robert Lewandowski goals at the Signal Iduna Park created history in the semi-finals for Dortmund, and for Madrid too, with their second heaviest defeat in Champions League history.
It was a chaotic night as the Polish striker ran riot, but marked an arrival for Klopp on the European stage after already beating Los Blancos in the group stages, topping their pot undefeated.
The semi, though, was an even bigger shock for a team coached by Jose Mourinho, containing legends of the game such as Cristiano Ronaldo, Kaka and Luka Modric, and they failed to come back from it.
Late goals from Karim Benzema and Sergio Ramos back at the Santiago Bernabeu weren't enough to stop another loss for Mourinho's Madrid, ending an era where they had dominated the game alongside Pep Guardiola's Barcelona.
Mourinho was soon sacked in what he called, "The worst season of my career," and reports claimed that Klopp's performances had already put his name on the list of replacements.
"Maybe the Madrid fans want a German Coach again," Klopp said of the news. "Unfortunately I have no time for them.
"The truth is that I have a contract at Dortmund until 2016 - the rest is just rumours.
"It shows that a lot of people have seen our games against Real Madrid and they have liked what they've seen.
"There's worse things that could happen."
Carlo Ancelotti eventually took the post with stunning results, breaking Madrid's hoodoo in Europe with a tenth Champions League title and their first in 12 years.
But despite Klopp signing up with Liverpool in 2015, that didn't take him off of Florentino Perez's radar, with Real coming back in for him on multiple occasions.
Klopp was again lined up when Ancelotti left in 2015, with former president Ramon Calderon explaining their eventual choice, Rafael Benitez, was fourth on the list.
The Benitez experiment was a disaster, but ultimately led to Zinedine Zidane and three Champions League titles, however, Klopp's reputation only increased.
When Zidane eventually left and caretaker manager Santiago Solari flopped, Klopp was again sought after, with Spanish outlet Don Balon saying his impact in 2013 was still felt.
"One of the managers that Florentino Pérez has repeatedly sought out is Jurgen Klopp, the work that the German has been doing is comparable to the best," they reported.
"It is only necessary to remember how the Borussia Dortmund that he coached at the time made life impossible for Madrid.
"No one understood how a team that went unnoticed by the rest of Europe could achieve such an exceptional performance, the answer to this was found on the bench.
"Their strategist imprinted on them a tension and tactical rigour that made any great team that they had to face reel away."
Fortunately for Madrid, it was them who made Klopp shudder in the 2018 final, unable to recover from an early Mohamed Salah injury and a Loris Karius disasterclass.
The 54-year-old lost again against Los Blancos in the quarter-finals last year, but his opinion from 2013 is still valid, as little has changed with Madrid's elite mentality.
"It's not that easy making these things against Real Madrid - they are cool as ice," he said.
"You have a chance against them and they are not bothered. It doesn't affect them. Have you seen them even one time, panicking because someone had a chance against them? Ice.
"They think, 'opponents have chances, it happens. We have a chance, we score'.
"Pep said once, the big teams really have a cup of coffee and then bang, they go. So you have a chance against them, you'd better take it."
It's easy to see how Klopp has learned from that lesson in recent years, with his current Liverpool side showing the same kind of steely psychology to compete on all four fronts this season, despite rarely playing at their best.
And when he takes on his suitors for the tenth time in Paris, Klopp will be hoping to turn the tables back the other way ending Madrid's heroic 2021/22 campaign of comebacks by making their lives impossible.