Dortmund have unexpectedly called a news conference for 13:30 CET amid reports that coach Jurgen Klopp will leave at the end of the season.
Bild reports that Klopp has asked for his contract, which runs until 2018, to be cancelled at the end of the current season.
Dortmund have endured a poor season and are 10th in the Bundesliga table, six points below the Europa League qualification places.
Klopp won back-to-back Bundesliga titles with Dortmund in 2011 and 2012, and led the club to the Champions League final in 2013, which they lost 2-1 against Bayern Munich.