The Borussia Dortmund boss has singled out the Portugal captain as Real Madrid's pre-eminent attacking threat and has again ruled out a move to the Blancos
Both sides previously met in the group stages of the competition, with Dortmund winning the home game 2-1 before drawing 2-2 at the Santiago Bernabeu, yet Klopp expects to face a very different Madrid next week - and is especially wary of the tournament's top scorer.
"Madrid are a very talented side that look for possession and to push forward. We can't leave Cristiano alone and we also have to attack," Klopp told AS.
"Madrid will be better informed about how to play against us. We're not at that stage yet. We'll have to wait a little while to find a solution.
"It's a fact that the team we played in the group stages is a very different proposition from the one we'll face in the semi-finals. In the group stages Marcelo was missing and there were attacking players out injured.
"Madrid will be stronger, but so will we. We're going to enjoy ourselves, but play hard and the simple fact that we're in the semi-finals is something very special for us."
The BVB coach then went on to discuss his future and stressed once more that he has no intention to leave Dortmund for Real Madrid.
"I'm going to be the coach of Borussia Dortmund next season unless something drastic happens and they get rid of me. Next year I will be in charge of Borussia; nothing more to say.
"If my name is being mentioned in Madrid as the possible successor to Mou, if he is leaving, then it's an honour. Next year I will be at Borussia, for sure."
The 45-year-old has a contract with Dortmund until June 2016.