The Germany international has a contract with BVB until the summer of 2017, but he has a buyout clause in his existing deal that would allow him to leave the club for €25 million at the end of the season.
Dortmund are keen to offer Reus a new and improved deal without a buyout clause - with Bayern Munich closely monitoring the 25-year-old's situation - but negotiations have been put on the back burner for now due to the club's poor start to the 2014-15 campaign.
Jurgen Klopp's men currently sit 15th in the Bundesliga table with just seven points from nine games.
"Nothing has changed about our intentions to continue our collaboration with Marco," Zorc told Sport Bild.
"But the current situation demands full focus from everybody at the club. Our biggest priority at the moment is to get out of this difficult situation. Everything else comes after that for now."
Reus recently returned to match action after shaking of an ankle injury. He has scored three goals in seven appearances for Dortmund so far this campaign.
Meanwhile, Bayern president Karl-Heinz Rummenigge has stressed that the 25-year-old remains an interesting player for the Bavarians.
"We know that he has a lot of quality," Rummenigge told Sport Bild.
"And we know his clause. For us a young German national player of such quality is interesting.
"But I do not want to make unrest in Dortmund."