Jurgen Klopp has sent Dortmund a note of warning, stating Liverpool will be ready for the second leg.
Liverpool got the better of Dortmund in the first leg, with Origi grabbing a vital away goal in the 1-1 draw.
Many are anticipating an Anfield backlash from Thomas Tuchel’s team but, speaking at his pre-match media conference on Wednesday, Klopp stressed that Liverpool also have room for improvement.
“I don’t think we were at our limit last week, and nor were BVB,” said the former Dortmund boss.
“Maybe some thought BVB would have an easier time of it. We created chances, and didn’t just defend. It will be the same tomorrow, a balance between attack and defence.
“Forget about last week, and we will face tomorrow night with a new attitude.
“We won’t be flying a white flag. BVB can play better, but so can we. We need to do better tomorrow night.”
Klopp was also eager to play down the potential significance of Origi’s away goal, adding: “It makes a difference only if you get the right result in the second game.
“Dortmund can score goals anywhere in the world so you can’t just try to keep the clean sheet. Maybe after 85-89 minutes the away goal will be relevant, but not earlier.
“Only at 0-0 is it an advantage. If we win, we don’t need it.
“This is a new start. We know about the quality of Dortmund. Now they know a little bit more about our qualities. We will see who handles it better.”
Last week’s first leg featured a special atmosphere at Signal Iduna Park, and Klopp has urged the Anfield faithful to respond in kind.
When asked about the kind of atmosphere he is expecting, Klopp replied: “Hopefully something I have never had until now!
“We have had wonderful atmospheres, but the best for sure was Man United [in the Europa League last 16], but we have to jump over that level.
“I don’t like atmospheres when they don’t get into the game. We have to do our job and be part of the atmosphere, show that we know what it is about.”