Borussia Dortmund CEO Hans-Joachim Watzke has hinted that Robert Lewandowski may be available at the end of the season.
The 24-year-old, believed to be of interest to Manchester United and Real Madrid, is out of contract in 2014.
Should the Pole resist attempts to extend his stay, Die Borussen would be forced to sell up next summer in order to command a substantial transfer fee.
"If Robert does not extended his contract, we will proceed as always," Watzke told Spiegel.
"Us three [coach Jurgen Klopp, general manager Michael Zorc and Watzke] will sit down together and discuss what to do next. The result is totally open."
Lewandowski scored 22 goals in 33 games in the Bundesliga last season.
