Speaking in his post-match press conference, as cited by Anfield Watch's Twitter account, Klopp explained what he said to his players at half-time after being down 2-0.
"At HT I told the boys to play better than the first half!" said Klopp. "Usually we try to find a situation to show them which explains it. I told them to find one situation. Pete Krawietz couldn't find any!
"It was clear, the start was difficult for us to take. We tried to force it and kicked too many long balls. It was never enough to gain momentum.
"So we explained what we had to do to get stronger and move smarter. We couldn't find the half-spaces, the front three were too fixed.
"There was no flexibility so we had to mix it up. We played into their hands.
"I told the boys I wanted to read the headline: 'The mentality boys are in town'. I wanted us to go for it. For me, it was like this."
"It was tough for Villarreal. They took a lot of risks. I cannot tell you what I said at half time. I was talking about playing football and showing up, being brave. It was a football problem.
"It's not that Luis was the solution - it was about moving more. Sadio, Mo, Diogo were playing against a man-marking system, we played into their hands. We couldn't keep one ball in the first half."
Anfield Watch Verdict
Whatever the German said it clearly worked. The players came out at half-time with a point to prove and they proved it.
Diaz has easily cemented his place in the starting XI of the Champions League final after that performance, he was unbelievable and his presence helped the Reds win tonight's game.
With the quadruple hopes still well and truly alive, hopefully the boys aren't too hungover after tonight's celebrations!