The 40-year-old had been unwell with a virus and missed the pre-match news conference on Tuesday prior to Bayern’s Champions League game against Arsenal.
The former Manchester City and Belgium defender was subsequently on the touchline for the match on Wednesday.
“Vincent Kompany had to seek medical treatment on Friday after collapsing during training for FC Bayern’s amateurs,” said a statement from the Bundesliga club.
“The first-team coach had been watching the second team’s session. Kompany will undergo thorough examination in the hospital and remain in medical care. For the time being, his coaching staff will manage training and match operations.”
Bayern’s next game is against Freiburg in the German top flight on Sunday.
“Vincent Kompany’s health is our top priority. We at FC Bayern will do everything we can to ensure his speedy recovery,” said Bayern sporting director Max Eberl.
“Vinnie will receive all the necessary medical care and support, and all the time he needs.
“His coaching team, in whom we have complete confidence, will take over his duties. Everyone at FC Bayern wishes Vinnie a speedy recovery.”
Aaron Danks, one of Kompany’s assistants, took the pre-match news conference for Bayern before the Arsenal game.
