Borussia Dortmund insisted they will now sell Robert Lewandowski to Bayern Munich in the summer, even if the player himself wants a move to Allianz Arena.
With just a year remaining on his contract, Lewandowski is expected to leave the Champions League finalists in the summer transfer window, with Bayern thought to be the most likely destination.
It is understood Bayern have already agreed personal terms with Lewandowski, who has his heart set on a move to the Bundesliga and Champions League winners.
However, having already lost Mario Gotze to Bayern, Dortmund are determined not to sell another prized asset to their title rivals.
"We have communicated to the player and his advisers that we will not agree to a transfer to FC Bayern this summer," Dortmund sporting director Michael Zorc said.
If Dortmund stick to their stance, they will be left with two options - sell Lewandowski to the highest bidder outside the Bundesliga, or make him see out the final year of his contract and then allow him to go on a free transfer next summer.
Manchester United are thought to be extremely keen on the 24-year-old forward, while the likes of Real Madrid, Chelsea and even Arsenal have been linked with a move.
Dortmund, however, said they are willing to keep Lewandowski, who had yet another brilliantly prolific season, at Westfalenstadion for another season and risk losing him on a free transfer, most likely to Bayern Munich.
Zorc also has no doubts Lewandowski will be fully committed to Dortmund's cause next season, despite being denied a move.
"There will be with him now perhaps a small phase of disappointment," Zorc said. "But then he will deliver his usual performance, as does a professional with character... and Robert has a whole lot of character."
