The announcement came just three weeks after Selmayr was given the new director role at the bank, and in the very week he was supposed to start there.
"We were so looking forward to working for Martin," said one sullen EBRD staffer.
"We'd organised a welcome party with homemade bunting and everything."
"My daughter did a smiley face on one of the flags. How am I going to break the news to her? I shouldn't have told her in the first place that daddy was going to be working for him. It's my fault," he said, before trailing off.
"And then there's the cake we had made," chipped in another sobbing EBRD official. "So cruel, to dash our hopes like that," she said.
"It's almost as if he never intended to take the job in the first place, but was handed it as a cynical manoeuvre to give him a promotion and payrise before moving into the Juncker chief-adviser role," she added. "But that doesn't bear thinking about. He wouldn't do that to us."
Staff said they only hoped Selmayr's placement at the head of Juncker's team was a temporary one, to help the former Luxembourg PM prepare to take over at the European Commission later this year.
"Because he's helpful like that, Martin is," said one. "Always thinking of others."