Liverpool were stunned last week when two goals from Gianluca Scamacca and a third from Mario Pasalic silenced the Kop as the Italian side appeared to take an impregnable lead.
"Directly after the game, everybody in the stadium in Liverpool – the Liverpool supporters, the Atalanta supporters, players and our staff – thought 'that's it'", said Klopp in his pre-match press conference on Wednesday.
"But now it is a week later and I don't think everybody thinks it is already decided.
"We are here and we can be good. Obviously we can be not so good as well. So let's see what we can put on the pitch tomorrow."
Klopp, however, stopped short of comparing Thursday's tie with the Champions League semi-final win over Barcelona in 2019 when they came back from a 3-0 defeat at the Camp Nou to win 4-0 at Anfield.
"What is similar? The result, definitely. The performance, not really.
"We played at that time an exceptional game and lost 3-0 (in Barcelona) and nobody knew how.
"I think we shouldn't have lost the last game (against Atalanta) 3-0 but we were not as great as we were then in Barcelona. And, we lost at home and we are now away, that's a massive difference.
"It's really not about comparing or whatever."
He added: "A lot of moments we had last week, really good moments, were unlucky but in the end they won, completely deserved.
"They played a really good game, we didn't play extremely well. So, that's it now.
"If we want to win the game then we better play good. If we play good we have a chance to win it and then we will see."
'100,000 percent focus'
Defeat by Crystal Palace at the weekend made a big dent in Liverpool's hopes of wresting the Premier league title away form Manchester City, giving the Europa League an added importance.
"It has our 100,000 per cent focus," said Klopp. "We are only here for one reason."
The German also looked to sow some seeds of doubt in the home side, suggesting that a 3-0 lead was almost as difficult to handle as a 3-0 deficit.
"It is not easy to approach a game when you are 3-0 up," he said, citing Liverpool's Champions League win in 2020 on their only previous visit to Bergamo.
"We had that in the past, when we won here in Bergamo 5-0.
"At home it was not easy to find the right mood for that game and in the end we lost 2-0, I think.
"It's really not simple because usually you fight for everyone and how do you want to fight tomorrow when you are 3-0 up?
"That's really not easy for them as well, so we will see who deals better with the situation and all these kind of things."
