Karius, however, says he's unlikely to do a Bruce Grobbelaar.
"I have not figured out any moves yet," says the 24-year-old. "It can help, but I would have to think a bit more about what is possible now. I have never been involved in a penalty shoot-out at senior level. You train for it, but it does not happen much.
"I will study the Real Madrid penalty-takers, of course. We have analyst guys putting clips together for us. We will have a goalkeeper meeting before the game to show us the opposition. I can put video on my iPad and keep taking a look, but you have to go with instinct a little bit. There is a mix. When you are standing on the line, there is a voice inside you that will tell you which corner he might put it.
"You can be the hero, but saving the penalty does not say if you are a good goalkeeper or not. "
Karius added: "The first knockout game against Porto was the moment I felt I was No 1.
"That was when it was made clear I was playing in all competitions. I played two or three good games in the Premier League and the manager told everyone, 'that's how it is now'. I knew I was staying in."