The defence has come under scrutiny in recent weeks, having kept just two clean sheets in 10 matches, but Karius insists the focus should not be placed exclusively on the back four, and in particular the two centre-halves, whomever they may be.
"Sometimes you need a punch in the face and we have had already a few - not too hard".
Will we still be talking about the defence? "There are no worries".
And though Klopp accepted that his side need to defend better as a whole, he claimed they will be prepared for any threat Spartak pose.
Liverpool drew their opening Group E match 2-2 with Sevilla at Anfield, while Spartak conceded a late equaliser in a 1-1 draw at Maribor.
He will make his second appearance in Russian Federation against Spartak Moscow and is determined to seize every opportunity. We're waiting to see if anybody latches onto Klopp saying "I love Harry Kane" and runs with a January transfer story.
"It's a healthy competition", Karius said.
"When you're a captain at a big club you've got to step up in big moments and produce special things. I love good footballers that is how it is".
After a hugely frustrating draw with Sevilla on Matchday One, Liverpool hope to pick up three valuable points in the Russian capital. Antonio Conte's long-time assistant Massimo Carrera struck out on his own, and last season he delivered Spartak's first league title since 2001.
Spartak Moscow also come into this weeks clash with several injury worries. They now sit seventh in the league table.
It's likely but at the moment nothing is sure.
"We were not really on the floor, but we always got up".