The reigning league and Champions League winners were beaten 3-2 at home by Paris Saint-Germain on Wednesday in the first-leg of their last-16 clash.
Eric Maxim Choupo-Moting and Thomas Muller helped the Bavarians fight back from 2-0 down to restore parity, but Kylian Mbappe netted a winner for the visitors, 20 minutes from time.
It was their first defeat in Europe since March 2019 while their seven-game winning run in all competitions came to an end too.
On the league front though, Hansi Flick's boys have maintained a fine run, winning each of their last five games and are firmly on course for a ninth consecutive Meisterschale.
They now come up against a stuttering Union Berlin side that has won only twice from their last 11 outings, dropping out of contention for the Europa Conference League in the process.
In what is only their second-ever campaign in the Bundesliga, the Iron Ones are still on their way to a top-half finish, after coming 11th in the end-season standings last year.
Bayern Munich vs Union Berlin Head-To-Head
There have been just four previous meetings between the sides, with Bayern Munich winning thrice against Union Berlin and losing none.
The only time the East Berlin outfit managed to hold the mighty Bavarians was in December last year in a surprising 1-1 draw.
Bayern Munich Form Guide (all competitions): W-W-W-W-L
Union Berlin Form Guide (all competitions): D-W-L-L-D
Bayern Munich vs Union Berlin Team News
The holders have quite a few injury concerns with as many as six players out injured, including talismanic striker Robert Lewandowski, who sustained a knee injury while on international duty with Poland. He won't return until the end of the month.
Leon Goretzka and Niklas Sule were both taken off against PSG with muscle injuries and will also be sidelined for this clash.
Serge Gnabry, Douglas Costa and Corentin Tolisso are out as well, while Alphonso Davies will be serving the second of his two-game ban.
Injured: Robert Lewandowski, Leon Goretzka, Niklas Sule, Serge Gnabry, Douglas Costa, and Corentin Tolisso
Suspended: Alphonso Davies
Sheraldo Becker and Anthony Ujah both underwent surgeries on the ankle and knee respectively and will hence be out. Leon Dajaku is also out of the game
Taiwo Awoniyi is unlikely to feature with some thigh problems while Niko Gießelmann is doubtful with a knock to his shoulder.
Injured: Sheraldo Becker, Anthony Ujah, Taiwo Awoniyi, and Leon Dajaku
Bayern Munich vs Union Berlin Predicted XI
Bayern Munich (4-2-3-1): Manuel Neuer; Benjamin Pavard, Javi Martinez, Jerome Boateng, Lucas Hernandez; Joshua Kimmich, David Alaba; Leroy Sane, Thomas Müller, Kingsley Coman, Eric Maxim Choupo-Moting.
Union Berlin (4-3-2-1): Andreas Luthe; Christopher Trimmel, Marvin Friedrich, Robin Knoche, Julian Ryerson; Christian Gentner, Robert Andrich, Grischa Prömel; Marcus Ingvartsen, Max Kruse; Petar Musa.
Bayern Munich vs Union Berlin Prediction
Bayern Munich have been significantly weakened by the raft of injuries currently plaguing their squad.
Yet they should have enough in the tank to see off Union Berlin and win for a sixth straight time.
Prediction: Bayern Munich 3-1 Union Berlin