"I have played twice here with two teams - Mainz and Dortmund - and it (the atmosphere) depends on the performance".
Roberto Firmino scored either side of Sadio Mane's header to put Liverpool 3-0 at half-time and leave the Reds on the brink of qualifying for the last 16.
It means Liverpool need a point at home to Spartak to now qualify but Sevilla could snatch top spot as they play already-eliminated Maribor.
"It's getting really exciting and decisive - and that's really cool", Klopp said. "To control the game, it's not allowed to become passive like this".
And just as he did in the Europa League final against the same opponents, Moreno had a nightmare as Liverpool let a three-goal lead slip against Sevilla, with the Anfield club forced to wait for their progression to the knockout stages to be confirmed. It was a goal to make Klopp wince.
Belgian Simon Mignolet has reigned supreme in the Premier League, but every continental fixture gives Karius the chance to prove himself further and Tuesday will be no different.
And Ferdinand was critical of the Spaniard, who was replaced in the second half.
It could have got even worse for Sevilla before they got into the shelter of the dressing room to regroup at half-time as Salah raced onto a lovely Coutinho through ball only to be denied by another smart Rico save. Sitting deeper at West Ham and curbing the attacking instincts of his full-backs, the former Sevilla player Alberto Moreno and Trent Alexander-Arnold, against Southampton were, he admits, part of the pursuit of stability.
Asked whether the £38million summer signing had exceded expectations with 14 goals in 18 appearances in all competitions Klopp said: "He has reached them at least, that's clear".
Not as composed as he was for England against Brazil but surely he should be playing centrally.
He was also far from in peak form tonight, as he continues to recover from a hamstring injury. That half, particularly the first half an hour, was goddamned mental.
Penalty. Oh no. Albi gives away pen.though, on second viewing it is a horrific simulation. "We have one real weapon - playing football - and we didn't do that in the second half before we conceded the second goal".
"It feels like we lost, but we didn't". If they cannot keep the ball, it inevitably goes to the opponents and the defenders are then subjected to too much pressure and eventually cave in. "The game will be about possession and losing the ball high up the field". It was 50 minutes [when Sevilla scored their first goal], that's a long time to try and stay in the game, you can score 10 times in that if you want. But this match continues to insist on being of the heart-attack inducing variety.