Star striker Lewandowski has been in outstanding form this season, with the highlight coming in the Champions League semi-final first leg, where he scored all of Dortmund’s goals in a 4-1 demolition of Real Madrid.

Should Lewandowski honour the remainder of his contract until the end of next season, he would be allowed to leave without Dortmund receiving a fee, but Watzke is keen for the Poland international to stay regardless.

"Our desire is still that he will play for us at least one more year until his contract runs out," he told Suddeutsche Zeitung.

Lewandowski has reportedly been subject to interest from the likes of Bayern Munich and Manchester United, and his agent has said that the striker is likely to move in the close-season.

Dortmund have already lost Mario Gotze to Bayern Munich ahead of next season after the Bundesliga champions triggered his release clause of €37 million, and Watzke was keen to stress that this type of deal will not be allowed to happen again.

"After winning two championships and going through to the Champions League final, we have reached a status where we expect every player to unconditionally commit to the club," he said.