Bayern Munich president Karl-Heinz Rummenigge reckons Bastian Schweinsteiger's situation at Manchester United could dissuade players from joining the Premier League club.
The 32-year-old is reportedly training with United's reserves after being told he does not feature in new manager Jose Mourinho's plans at Old Trafford.
Schweinsteiger was not among the 22 players used by Mourinho in Wayne Rooney's testimonial match against Everton on Wednesday.
And Rummenigge is baffled by the development towards Schweinsteiger, who retired from international duty with Germany at the end of July.
"I could hardly believe it. One or two players are going to think long and hard in future about whether they want to go to such a club," Rummenigge said.
"Nothing like that has ever happened at Bayern Munich."
Schweinsteiger forced his way back into the first-team fray at Bayern after being told in 2005 by then-coach Felix Magath to train with the reserves since he did not have a place for him in the first team.
The midfielder bounced back to inspire Bayern to a league and cup double, contributing to his haul of eight Bundesliga titles, seven DFB-Pokals and the 2013 Champions League title with the club.
He was also a key part of Germany's 2014 World Cup triumph, and won last season's FA Cup with United.
Ottmar Hitzfeld, who gave Schweinsteiger his professional debut at the age of 18 and won the Bundesliga with him in 2003, has also condemned the situation.
"It's a lack of respect for a worthy player," Hitzfeld said. "It's a method which is strange to me.
"Schweinsteiger is a key player, a world champion, a personality, while at the same time he has an exceptional attitude."