Arsenal have been in talks with Dortmund this week to discuss a deal but are yet to reach an agreement.
And after Aubameyang was named in the Dortmund team to face Freiburg, Zorc provided an update on the situation.
“We know the change request, but we have a clear position, and we only implement a transfer if the parameters suit us,” Zorc told Sky Sports Germany.
“Arsenal has started several attempts that we have declined, so I can not say how it will end at the moment.”
Aubameyang has not played for Dortmund since December 16 but he has trained all week with his team-mates.
And Zorc says that after behind the scenes talks, he is confident the 28-year-old would be focused enough.
He added: “He’s in because he has been training well for the last ten days, so we have to look soberly, we had two wrongdoings that we sanctioned too.
“Now we could calm it down, have talks with the family and we’re sure he’ll perform well and there are no problems with the team.”