Bayern Munich CEO Karl-Heinz Rummenigge has criticised Manchester United for reportedly demoting Bastian Schweinsteiger to the reserves.
Schweinsteiger, who turned 32 on Monday, is reportedly training with United's under-23 squad after being told by Jose Mourinho that he has no future at the club.
"I could hardly believe when I read it," Rummenigge told a news conference on Wednesday. "This never happened before at Bayern Munich and never will happen."
Schweinsteiger left Bayern for United last summer and made 13 Premier League starts during the 2015-16 season.
Rummenigge added: "In the future players will think twice before joining such clubs, who treat them more radically when they want to get rid of a player than a club like Borussia Dortmund or Bayern Munich in the Bundesliga would do.
"It seems like this is the price players have to pay if they join these clubs."
Former Bayern coach Ottmar Hitzfeld told RND the Schweinsteiger situation showed "a lack of respect" and added: "This method is alien to me."
The United midfielder made a total 31 appearances under former manager Louis van Gaal in 2015-16, with a knee injury keeping him out for several months.
"He was not number 15 in the pecking order, but a key player, a world champion and a personality -- he also has an outstanding character. A player like him hasn't deserved that at all," Hitzfeld said.
Meanwhile, Bayern coach Carlo Ancelotti has ruled out the prospect of the 32-year-old returning to the Allianz Arena.
"Schweinsteiger is not a part of our idea. I don't think now is the time to come back to Bayern Munich," he told his news conference on Wednesday.
However, Rummenigge has said he can envisage Schweinsteiger returning to Bayern in a non-playing role in the future.