But with 18-months remaining on his current deal, the German star insists that Dortmund have not given him an ultimatum about his future.
The 23-year-old has been strongly linked with English champions Manchester United, whilst Real Madrid are also said to be very keen.
However, Gundogan - who has just left the side's winter training camp in La Manga and returned to Germany due to illness - is open about his future.
"I have not made a final decision yet," he is quoted by German daily Bild.
"BVB are the first team I am talking to, I will soon make a well-thought decision. But I am keeping my options open at this point.
"Borussia Dortmund have not set me an ultimatum.
"I am just trying to get healthy again and get back to my best form. That's the main priority for BVB and for myself."
@marrowak . U used the term 'mercenary teams' ( adjective) . Therefore I was right with my reply as mercenary describes the act of doing something for a personal gain so by BM & RM signing/targeting the 2 players mentioned it is for personal gain . No other team can sign them thus preventing potential opposition from utilising their skill and ability in games against them so this in itself is mercenary behaviour . A bit premature in ur assessment of Kagawa i feel . But then again liverpool would know all about the incorrect use of a former BVB player of the season , didn't Mr Rogers use Sahin in the wrong position or am i getting that wrong ?- ted crilly