Borussia Dortmund sporting director Sebastian Kehl admits the club have looked at defender Ramy Bensebaini but nothing confirmed.
Werder Bremen announced on Thursday that defender Anthony Jung has extended his contract with the Bundesliga club.
Manchester City had to settle for a 1-1 Champions League draw at RB Leipzig as their first-half domination went to waste.
RB Leipzig coach Marco Rose accepts his side have a tough task to stop a player "crazy about scoring" in Manchester City's Erling Haaland.
Dortmund's Mahmoud Dahoud will be leaving the Bundesliga club when his contract expires in the summer.
Borussia Monchengladbach could be hampered by fitness concerns of two key players ahead of their fixture against Bayern Munich.