Bayern Munich's board are frustrated with coach Thomas Tuchel's public complaints about their summer market work.
Bayern splashed out 120m to prise Harry Kane away from Tottenham, while Konrad Laimer, Kim Min-Jae and Raphal Guerreiro also arrived. However, a move for Declan Rice fell through as Arsenal stepped in, while Joao Palhinha missed a deadline day switch from Fulham.
After victory over Borussia Monchengladbach, Tuchel said: "The squad is a bit thin, a bit small.
"We have six trained defensive players for a four-man chain, which is perfect."
BILD says Tuchel's comments have been deemed "negative" by Bayern chiefs and met with "incomprehension" by the board. Directors insist they tried everything to close a deal for Palhinha last week.
It's also suggested Tuchel wanted Bayern to sign Rice ahead of Kane, while the board were baffled by some of the names the coach suggested as transfer targets.