Watzke has dropped the biggest hint yet that Jadon Sancho could be sold in the summer transfer window.
His announcement comes amid reports Dortmund have slashed Sancho's price tag, and would now accept up to £20million less for the England international.
Manchester United agreed terms with Sancho last summer but Dortmund refused to drop their £108m valuation.
"In the midst of a pandemic, I no longer rule anything out," Watzke told Handelsblatt.
"But it is not necessarily aspired to. Above all, there is the financial balance: that we have a strong team on the field and are economically stable at the same time. Asking banks for credit lines at the drop of a hat just to avoid selling a player will not be our way."