The German international has been a key part of Dortmund's success over the last couple of seasons, but the emergence of Erik Durm has placed his long-term future in doubt.
While revealing that he feels "very good" at Dortmund, the 26-year-old has said that it is "nice" to learn of outside interest, with Liverpool strongly linked with a move for the full-back.
"Of course I look forward to hearing things like that and it's nice when top clubs are interested in you," he told WAZ.
"But I still have a contract with Borussia Dortmund until 2016 and I feel very, very good at BVB."
A number of European clubs are believed to be monitoring proceedings.