The Belgian was overseeing Bayern Munich II on Friday, having returned to the touchline in the Champions League encounter with Arsenal on Wednesday.
The former Manchester City captain had suffered an illness in the lead-up to that match, which finished as a 2-2 draw at the Allianz Arena, amid rumours that he would not be able to watch his side from the technical area.
Aaron Danks, his assistant manager, had taken over first-team duties in the interim before Kompany’s return, but the ex-defender’s health took another turn on Friday as Bayern released a statement.
Quick return: Vincent Kompany
AFP/Getty
"Vincent Kompany had to seek medical treatment on Friday after collapsing during training for FC Bayern's amateurs," the statement read.
"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 return to Bundesliga action against Freiburg on Sunday.