Thomas Tuchel said he felt sorry for Harry Kane after watching his side go down 3-0 to RB Leipzig in his new star signing's debut.
"I have no explanation right now," Tuchel said in a post-match interview.
"We're conceding the easiest goals. It's as if we haven't done anything for four weeks. What we've shown today has nothing to do with the way we've been training, the form, the atmosphere. It's alarming, just alarming."
The club's new record signing, Harry Kane, came on after just over an hour but never made his mark on the game on what was a night to forget for both him and Bayern.
"I just feel sorry for him," Tuchel said when asked to comment on Kane's debut.
"He probably thinks we haven't trained for four weeks. Our performance today had nothing to do with what we wanted to do. It's a very bitter evening, I'm sorry."