Borussia Dortmund chief exec Hans-Joachim Watzke admits they must sell this summer to ease financial pressure.
"The money we are currently losing will take a long time to recover from, it will not go fast. I think it will take at least five years before we reach the status we had before the virus struck," says Watzke.
"We are in the middle of a pandemic and then I can not rule anything out. We may need to sell a key player. But at the same time it is not our goal, we want a strong team on the field but at the same time a stable economy.
"If we are to play without an audience next season as well, it is something we will need to consider. We will not ask for a bank loan just to be able to keep a player."