Borussia Dortmund CEO Hans-Joachim Watzke has claimed the club had no choice but to include a €25m (£20m) release clause in Marco Reus' contract when they signed him in 2012 – as it was the only way to beat other suitors.

Reus' future at the German giants has been under scrutiny in recent weeks after a special release clause in his contract was revealed that allows him to leave Dortmund next summer for as little as €25m.

Manchester United, Liverpool, Barcelona and Atletico Madrid were quickly alerted to the bargain price while reports suggested Dortmund would rather sell him this summer for around £30m than lose him to big rivals Bayern Munich the following year for £20m – after Pep Guardiola's side already took both Mario Gotze and Robert Lewandowski from them.

While nobody understands how such a talented player could be on the market for such a cheap price, Watzke has responded to the critics in an interview with WAZ claiming that they had no choice.

"He came from Gladbach to Dortmund and there were perhaps people around him, who told him: 'If maybe this does not work, then there is an exit.' At that time we were not at the level of today," he said.

"From today's perspective, there would certainly have been no get-out clause, but at the time he wanted one, there were ten deals on the table and we had to compromise.

"If we had not done it, then he would not be with us today. We will do a lot to convince Marco that his future is here. And also with us he has the chance to win a title every year."

Nevertheless, Watzke is still confident Reus will snub a potential move away and decide instead to commit his future to Dortmund with a new contract.

"I know Marco, I think quite well and I can say that things with him are not primarily about money. We will hold talks with Marco, in which it will be important to show our total package.

"It consists of the economy, ambitions and extreme confidence that we give to the player. I have a feeling that our players are happy with us. For those who have moved, I had the impression it was not always compelling. To put it mildly.

"Marco Reus as a player from Borussia Dortmund can characterise an era, as a legend. This is, for my taste, much more important than two titles more on the CV."