Schalke chairman Clemens Tonnies wants an explanation from coach Felix Magath for his side's 5-0 loss to Bundesliga new boys Kaiserslautern.
The defeat came just three days after the Royal Blues booked their place in the Champions League knockout stage with victory over Lyon.
"I am shocked," Tonnies told the Bild newspaper.
"For all the euphoria from the Champions League to be shattered by a newly-promoted team, that is a hammer blow.
"The coach and manager Felix Magath now has to explain and how we get out of this."
The defeat left Schalke, who had been expected to challenge for the title, fourth bottom of the table, just a point above the drop zone.
Tonnies, though, appears ready to stand by his coach.
"We are talking about the performance of the team," he added.
"I have no worries about Schalke getting relegated. But I had and have a much higher expectation in Felix Magath than just survival."