The Bayern manager will not be in the dugout at the Allianz Arena for his side's opening game of the new European campaign.
This boosts Man United's hopes of an unlikely win away in Germany as they desperately search for some positivity this season.
Tuchel is usually incredibly animated on the sidelines and his absence from pitchside is likely to impact his team.
Why is Tuchel not on the bench against Man United?
Tuchel will not be in the dugout for this Group A tie as he is suspended.
The former Chelsea boss received a red card in the second leg of Bayern's quarter-final tie against Manchester City last season.
READ MORE ON CHAMPIONS LEAGUE
Lionel Messi was in awe and footage caught Ronaldinho's stunned reaction to Joe Hart
Saudi Pro League director says clubs aren't 'throwing money' around and rejects UCL claims
He vented his frustration at referee Clement Turpin after a foul by Aymeric Laporte and had to be held back by his coaching staff.
Due to his actions, he was dismissed and his side were knocked out, meaning the punishment moved over into this year's competition.
Therefore, Tuchel is serving his suspension this week and will not be on the sidelines.
He is set to be replaced by assistants Zsolt Low and Anthony Barry who will take over first-team duties during the game and in the dressing room.
Most read in Champions League
AC Milan v Newcastle LIVE commentary: Magpies make European return at historic San Siro
Newcastle expected to avoid punishment despite breaking UEFA rules with late arrival
Nobody wanted Newcastle in the Champions League - the fans and Howe are a powerful combo
Bayern Munich vs Man United LIVE commentary: Kane faces Red Devils in European showdown
The usually-animated 50-year-old will have to watch on from a distance as his side take on a struggling United side.
United come into this game off the back of a humiliating 3-1 home defeat to Brighton in the Premier League as they battle issues on and off the pitch.
But with Tuchel absent, Erik ten Hag will see this game as an opportunity to put their poor start to the season behind them.