Julian Nagelsmann reportedly seemed intimidated in a furious dressing room row with Sadio Mane about his lack of game time, before the Bayern Munich boss was sacked.
According to Bild, the argument came after Bayern's 2-0 win over PSG in the second leg of their Champions League last-16 tie on March 8.
They claim Mane was enraged at only being given eight minutes off the bench and angrily confronted Nagelsmann in front of shocked team-mates, who noted that the 35-year-old boss appeared intimidated.
Nagelsmann had waited until the 82nd minute of the game to bring on Mane, with the Germans progressing comfortably, 3-0 on aggregate.