The Bundesliga champions are already through to the knockout round of the competition as Group A winners, so it will be a pressure-free contest for the visitors.
Man United, though, need to beat Bayern and then hope that the other match in the section between Copenhagen and Galatasaray finishes level, in order to advance to the round of 16.
Bayern will enter this match off the back of a shock 5-1 defeat to Eintracht Frankfurt in the Bundesliga on Saturday, and Tuchel has named a strong squad for the European contest, including England captain Harry Kane, who has scored 22 times during an excellent season to date.
Serge Gnabry is a notable absentee, with the ex-Arsenal youngster picking up a tendon problem during the defeat to Frankfurt in the league.
Sven Ulreich, Matthijs de Ligt, Bouna Sarr, Tarek Buchmann and Gabriel Marusic are also unavailable for selection through injury and have therefore not made the trip to England.
"They are always a dangerous team," Bayern boss Tuchel told reporters during his pre-match press conference. "My experience is that it is always dangerous to play Manchester United. They have a certain aura and certain mentality that makes them difficult to defeat.
"I feel that is part of the DNA of the club that they can overcome difficult minutes and difficult moments. You see in their strong moments how strong they are and the stadium [Old Trafford] plays a big role. The spectators are emotional and the stadium creates special moments.
"It is a difficult place to come and play, but it is a good challenge for us. For me personally, a game in Manchester United is always a big game. It cannot be described in any other way.
"It [Old Trafford] is one of the biggest stages in football. It has a certain aura and electricity around it. When they are good, they are really, really good and very dangerous in all positions."
Bayern recorded a 4-3 win over Man United in the reverse match in the group at Allianz Arena, while they have also beaten Copenhagen and Galatasaray (twice) in the section.
The German champions were held to a goalless draw by Copenhagen in their last match in the group, though, meaning that they have not been victorious since overcoming FC Koln in the league on November 24.
Bayern squad vs. Man United:
Neuer, Peretz; Davies, Guerreiro, Kratzig, Mazraoui, Min-jae, Upamecano; Goretzka, Kimmich, Laimer, Pavlovic; Choupo-Moting, Coman, Kane, Muller, Musiala, Sane, Tel