Reuters Ilkay Gundogan's future at Dortmund remains uncertain.
"It is our absolute desire that besides Robert Lewandowski no other regular player leaves the club," Watzke told The Daily Star.
"Only in the case of Ilkay Gundogan, we do not yet know how it will turn out. We would love to extend (a contract) with him."
The 23-year-old is confronted with a spine injury in the ongoing 2013/14 season, which has kept him on the sidelines for the last three months.
Nevertheless, he has already proven himself on the biggest stage of club football when he helped Dortmund reach the apex of the Champions League in the 2012/13 season. He has also received 8 caps from the Germany senior squad.
Arsene Wenger, who has openly expressed his admiration for Gundogan, will have to part with £25million, Dortmund's valuation, before he could have a chance to secure the midfielder's signature.
Meanwhile, Manchester United could provide the Gunners a stiff competition as David Moyes has also made it known that he is interested in bringing Gundogan to Old Trafford, to strengthen the Red Devil's midfield.