• Senegal forward Mane has been suspended from Bayern's squad before Saturday's Bundesliga match against Hoffenheim.
• Tuchel said the league leaders had "cleared the situation".
Bayern Munich will not "tolerate" the "heavy incident" in which Sadio Mane allegedly punched team-mate Leroy Sane, manager Thomas Tuchel has said.
Reports in Germany claimed Mane hit Sane in the face after Tuesday's 3-0 Champions League defeat by Manchester City at Etihad Stadium.
Senegal forward Mane has been suspended from Bayern's squad before Saturday's Bundesliga match against Hoffenheim.
Tuchel said the league leaders had "cleared the situation".
"It was a heavy incident - it was very important that it was cleared before the next training session," he said.
"I've known Sadio for many years - he is a top professional. He's never had a situation like that. He is focused on football, he has my full confidence. Everybody has the right to make a mistake," Tuchel added.
""This was too much - he apologised and I believe him. It was important that he stays in training, but he is suspended and he will be fined. I don't know where the money will go, the club and the player will decide. It is not my highest priority."It would be nice if things that happened in the locker room stayed in there. We don't need situations like that to prove our squad is alive. We don't tolerate things like that."
Bild said former Liverpool player Mane, a two-time African footballer of the year, had complained about the way Germany winger Sane spoke to him after the defeat.
Neither player has commented on the alleged altercation.
Bayern host Manchester City in the quarter-final second leg on Wednesday.