Source: Fanatik
More info + extended quotes:
Ceyhun Kazancı, Besiktas’ sporting director, on Weghorst's "goodbye":
I don’t understand why Weghorst said goodbye to the fans, why he made such a move. He is our football player right now. Our contract expires at the end of the season.
If Manchester United or any other team wants Wegnorst, they will meet with Burnley anyway. Burnley will then contact us and discuss the terms of separation. If we accept, the contract will be terminated. Otherwise, it will go on until the end of the season. He can’t just go. There will have to be a reward for us to approve the separation. I’ll give an example. Burnley told us, ‘We made a deal with this team for Weghorst. We give you half of the transfer fee.’ This may be a different condition. Then we’ll sit down and talk.