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.
Wir informieren heute um 13.30 Uhr auf einer Pressekonferenz. // There will be a press conference at 1330 CET today.
- Borussia Dortmund (@BVB) April 15, 2015
The Bavarians also beat them in the 2014 DFB Pokal final and signed key players Mario Gotze and Robert Lewandowski from their rivals.
Dortmund's signings, such as Henrikh Mkhitaryan in 2013 for a club-record transfer fee of €27 million, Ciro Immobile, Adrian Ramos, and Kevin Kampl have struggled to impress this season.
Klopp, who was appointed coach at the Westfalenstadion in 2008, has previously said he would be open to managing in the Premier League.
German tabloid Bild reports Dortmund have targeted former Mainz coach Thomas Tuchel as his successor.
Tuchel had been linked with the post at Hamburg, only for the side to appoint Bruno Labbadia on Wednesday.