The Liverpool boss admitted his side have made mistakes during the group phase in which they have lost every game on the road.
But he insisted tonight was the night to put things right by keeping it “tight at the back” and tapping into the emotion pouring down from the stands.
“It is a mix of being really lively, and making an emotional game of it – it must be. On the other hand we have to be really closed at the back so nothing happens there,” he said.
“That is a big job to do. We do not need to make it any bigger than it is, but it is big.”
Liverpool need to win 1-0 or by two clear goals against Napoli in order to progress.
If they fail to do so, they would drop into the Europa League only if Red Star Belgrade lose against Paris St Germain in the other Group C fixture. PSG superstar Neymar is expected to be back for that match after being out with a groin injury.
“We didn’t win often enough to be through already,” said Klopp. “That is our mistake and now we can put it right if we perform.
“But if we are not a Champions League club in January or February it will not be one second an excuse for anything else.”
Klopp admitted Napoli will be a tough opponent but maintained they were not unbeatable.
“No team in the world is perfect – we are not and Napoli is not,” he said. “We all have weaknesses. It is about using the weaknesses of the opponent.
“If we are really in the game and the crowd is there, then we can do the extra yard.
“That will be necessary for this game, 100 per cent.”