The Italy international endured a difficult debut season in Germany and is a reported target of Serie A clubs Napoli and Fiorentina.
Immobile’s agent Marco Sommella said to the Italian press: “I believe Borussia Dortmund have taken Ciro off the market.”
Immobile, the top scorer in Serie A in the 2013-14 campaign, joined Borussia from Torino last summer but made just nine Bundesliga starts and scored thee goals.
The 25-year-old is under contract with Borussia until June 2019.
The arrival of coach Thomas Tuchel as a replacement for Jurgen Klopp could see Immobile earn more playing time at Dortmund.
Klopp stepped down after seven years at the helm of Borussia this summer.