Borussia Dortmund chief exec Hans-Joachim Watzke admits they must sell this summer to ease financial pressure.
Jadon Sancho is likely to leave, with Manchester United and Real Madrid both keen.
"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."
