Although the Poland international's current deal does not expire until the summer of 2014, Dortmund director Michael Zorc admitted that the club could look to cash in.
"Robert Lewandowski is not going to sign a new contract," Sky Sports News quotes Zorc as saying. "We will have to see if he is going to be on the move in the summer.
"His contract runs until 2014. There are two options. Either he goes in June or he stays for another year."
Lewandowski has scored 19 goals in 27 appearances for Dortmund this season.