The 45-year-old coach says that he has heard nothing of the Poland striker's alleged agreement with Bayern Munich over a summer switch to the Allianz Arena
The Poland international's agent has claimed that his client, who has just over a year left on his current contract with die Schwarzgelben, will be joining Bundesliga rivals Bayern Munich this summer.
However, Klopp insists that he knows nothing of Lewandowski's alleged move to the Allianz Arena and claims that he has been left baffled by the comments made by the striker's representative, Maik Barthel.
"My understanding is that Robert will still be here next year," the Dortmund coach told reporters at a press conference on Thursday.
"The fact is that we are going very well this season. Why should we care about next year? Nobody knows what will happen next year.
"I cannot understand why an agent is speaking about a player that is under contract. I have many strange thoughts about all of this."
Meanwhile, Klopp revealed that Lewandowski's international and club colleague, Lukasz Piszczek, is a doubt for the second leg of Dortmund's Champions League semi-final tie with Real Madrid.
"He's definitely out of the game against [Fortuna] Dusseldorf this weekend," the coach explained. "And it's even going to be tight for the return fixture against Madrid on Tuesday."
Dortmund hammered los Blancos 4-1 in Wednesday night's first leg at Signal Iduna Park, with Lewandowski scoring all of the home side's goals and Cristiano Ronaldo grabbing Jose Mourinho's side's solitary away strike.