Klopp said: "It was clear we gave ourselves a massive hurdle. I liked the game a lot tonight with the desire and power the boys show. It was incredible from them.
"It was really tricky and we were too hasty in moments. If Trent Alexander-Arnold had been a bit fitter we could have gone a bit longer, but it is insane that he has even played! In the end he was running out of gas.
"We won the game and that was the reaction we wanted to show. It was difficult and we knew it would be but they deserve to go through 100%.
"We have to focus on the league and that is exactly what we will do from now. Tonight we won the game so we are back to winning ways. We have a few days to recover to go again against Fulham. That will be a different game but it will be tricky."
On how he is feeling, he added: "It is mixed emotions. We are out but I am happy with the game. We would have wished that we could have gone to Dublin but that hasn't happened.
"We now have one competition left and we will throw ourselves into that completely."