Borussia Dortmund chief Hans-Joachim Watzke has put Premier League clubs on notice over Robert Lewandowski.
The Poland striker is inside the final two years of his current deal and is interesting the likes of Manchester City, Chelsea and Arsenal.
"This is a very simple calculation. It may make economic sense after a good season with Lewandowski to cash in for as high a transfer fee for him as we can. But we are under no economic pressure to do something," said Watzke.
"There's always the possibility that we will, if he does not extend. To clarify one thing: we'll decide that alone. But of course we will discuss it also with him."