Following a two-month break owing to the coronavirus pandemic, the reigning champions and current pacesetters are looking to maintain their advantage at the top of the division.
The prolonged pause in proceedings come at a bad moment for Bayern given that they were on an incredible run of form at the time of the shutdown, winning 10 of their last 11 matches.
The most recent of those wins came at home to Augsburg on March 8, although it remains to be seen exactly what shape Bayern's players will be in 70 days on from that last outing.
As well as swatting aside Chelsea 3-0 in the first leg of their Champions League last-16 tie and overcoming Schalke 04 in the German Cup quarter-finals, Bayern have also gone 11 games without defeat in the league.
Incredibly, they have collected 31 points from the last 33 on offer to leapfrog Borussia Dortmund and RB Leipzig into top spot.
They head into gameweek 26 with a four-point lead on closest challengers Dortmund, whom they still have to play before the end of this rather unique campaign.
No team in any competition has stopped Bayern from winning since Borussia Monchengladbach in early December, but this may be the perfect time for Union to face the champions.
The same will be true for Union, of course, given that they have also had little time to get themselves back to full fitness, but the break has given them a chance to refocus.
They are eight points above the relegation playoff spot with nine games to go, while Wolfsburg in seventh place - enough for European football - are only six points better off.
Union, much like Bayern, still have plenty to play for, then, and they certainly have the ability to give the champions a run for their money on home soil - even if this match is behind closed doors.
Urs Fischer's side have won five of their last eight Bundesliga home matches, keeping a clean sheet in each of these five wins, suggesting that an upset should not be entirely ruled out.
Union Berlin's Bundesliga form: LWLWDL
Union Berlin's form (all competitions): WLWDLL
Bayern Munich's Bundesliga form: WDWWWW
Bayern Munich's form (all competitions): WWWWWW
The two-month break has given Bayern striker Robert Lewandowski, the division's top scorer with 25 goals, a chance to recover from a knee injury.
Niklas Sule may play again this season after being given time to recover from a long-term knee injury, though this game will come too soon.
As for the home side, Yunus Malli is not back in full training after recently testing positive for COVID-19.
However, captain Christopher Trimmel will be back involved after serving a suspension before the coronavirus-enforced shutdown.
Union Berlin possible starting lineup:
Gikiewicz; Subotic, Hubner, Schlotterbeck; Trimmel, Gentner, Andrich, Lenz; Ingvartsen, Bulter; Andersson
Bayern Munich possible starting lineup:
Neuer; Pavard, Alaba, Boateng, Davies; Thiago, Kimmich; Gnabry, Muller, Coman; Lewandowski
We say: Union Berlin 0-1 Bayern Munich
Bayern cannot afford to slip up as they go in search of an eighth successive title, while Union still have an outside chance of qualifying for Europe. The hosts have been impressive at Stadion An der Alten Forsterei of late, but we are backing the visitors to grind out another win in what will be just the second competitive meeting between the sides.