The Turkish international left the Westfalenstadion last summer for €10 million, but has had limited game time under Jose Mourinho, a frustration which has not been helped by a troublesome knee injury.
BVB did not want to lose Sahin in the summer, although the side have received a recent boost by the news that the highly-coveted Mario Gotze is looking to stay at the club, and Watzke is adamant star players staying in Dortmund will be a common theme of the future.
"The tendency to go to Bayern Munich has not been around for the past two years. We have seen this through contract extensions, as with that of Mats Hummels [in whom Bayern expressed interest last season]. The players know that we are an ambitious club in which the individual is very much appreciated," the chief executive told Der Westen.
"With us, ever player is fully integrated with his strengths and weaknesses. You can see in the example of Nuri Sahin what a player is capable of in the right environment. In another environment [Real Madrid], he finds it much more difficult."
Watzke then moved on to talk about Dortmund's strengths and compared his side to direct rivals, Bayern Munich.
"BVB have no specific weakness but there is a disadvantage. Bayern, with whom we have a respectful, cooperative relationship have been successful for 40 years. The club name occupies the entire city in which they now have no more competition," he added.
"In the last five years, Bayern have only been champions twice but they keep coming back."
The CEO concluded by talking about the future of the club, a future he believes to be very bright.
"We have the largest stadium and are growing in all areas. The club's prospects are great but they core business, performance in football, is most important. If we are successful and passionately play football, we have plenty of opportunities," he added.
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