Borussia Monchengladbach sporting director Max Eberl admits Thorgan Hazard will leave this summer.
He told the club's website: "We made our intentions to extend Thorgan's contract clear a while back now, but he hasn't reciprocated that interest.
"He has now told us that he doesn't want to extend his contract and instead wants to take the next step in his career by leaving the club.
"However, he still has a contract with us until 2020 and there is no release clause.
"Interested parties have to offer us a transfer fee that recognises his worth as an exceptional Bundesliga forward and a regular feature in one of the best national teams in the world.
"If it ends up being the case that Thorgan leaves us, then we will do what we've done well in the last few years - we will take the money we make from the transfer and use it to buy more exciting players for our team."