Last week's defeat in Der Klassiker means Bayern are now 13 points adrift of Bayer Leverkusen, so an almighty collapse will be required if Xabi Alonso's side are to throw away the title from here.
Match preview
The 2-0 loss to Borussia Dortmund last Saturday ended an 11-game unbeaten run in the fixture for Bayern, as goals from Karim Adeyemi and Julian Ryerson sunk the Bavarians in front of their home crowd.
It was also the first time Bayern have failed to beat Dortmund at home in the league for a decade, as the previous nine Bundesliga meetings at the Allianz Arena had seen Bayern win all nine, scoring 37.
Manager Thomas Tuchel, who will leave at the end of the season, conceded that their title chances are now gone, after Leverkusen left it late to beat Hoffenheim last week, extending the gap to an almost-unassailable 13 points.
Bayern's only chances of silverware now lie in Europe, as they will face Arsenal in a two-legged quarter-final in the Champions League over the next two weeks.
While Tuchel and the Bayern side may have their attention elsewhere, this will be Heidenheim's biggest game of the season, at home to the biggest club in the land.
This is their first-ever competitive meeting here, as the previous two were both at the Allianz and provided the neutrals with two incredible games of football.
Bayern won 4-2 in the reverse, coming back strongly after being pegged back to 2-2 from 2-0 up, but that was nothing in comparison to the remarkable encounter the two had in the DFB-Pokal quarter-finals back in 2019.
Frank Schmidt was also in charge back then, facing Niko Kovac, and after going 1-0 down, Heidenheim then got a boost as Bayern were reduced to 10 men, and they quickly went 2-1 up.
Bayern's quality against what was at the time a second-tier club was evident, and they rallied to go 4-2 up, but Heidenheim would not let up and levelled at 4-4, before Robert Lewandowski's late penalty sealed a dramatic 5-4 win for the Bavarians.
In their debut Bundesliga season, Heidenheim have been excellent, with safety all but assured and still an opportunity to make a run for Europe.
Those hopes for a first-ever continental appearance took a hit last weekend though, as Stuttgart denied them from a huge three points late on in a thrilling 3-3 draw.
After going 2-0 down, Alexander Nubel's own goal got Schmidt's men back into the game, before Tim Kleindienst netted twice in 60 seconds with five minutes to play to put them 3-2 up, but Deniz Undav snatched a point for the hosts in the eighth minute of additional time.
While the draw was ultimately still a good result, and they are just six points off seventh, it extended their run of form to one win in 11 games.
They have only lost three of those 11 though, but more wins will be required if they are to make a serious push for a possible Europa Conference League spot.
Heidenheim Bundesliga form:
L
D
L
L
D
D
Bayern Munich Bundesliga form:
L
W
D
W
W
L
Bayern Munich form (all competitions):
W
D
W
W
W
L
Team News
After last week's brace, Heidenheim's Kleindienst is just one away from hitting double figures in the top flight for the first time, after getting 25 in the second tier last season.
Following his introduction from the bench, Nikola Dovedan was sent off in injury time shortly before Stuttgart's equaliser last week and will be suspended here.
Elsewhere, Adrian Beck, Thomas Keller and Elidon Qenaj remain the three players on the sidelines for the hosts with injury.
Harry Kane failed to add to his tally of 31 league goals last weekend, meaning he is running out of time if he wants to catch Lewandowski's Bundesliga record of 41.
The England striker will be looking ahead to his return to North London in midweek when Bayern face Arsenal, and Manuel Neuer and Raphael Guerreiro may be rested here to ensure they are fit and ready to face the Gunners on Tuesday.
Sacha Boey remains out injured though, with fellow right-back Noussair Mazraoui still recovering from illness.
Heidenheim possible starting lineup:
Muller; Traore, Mainka, Gimber, Fohrenbach; Schoppner, Theuerkauf, Pieringer; Dinkci, Kleindienst, Beste
Bayern Munich possible starting lineup:
Ulreich; Kimmich, Kim, Upamecano, Davies; Laimer, Goretzka; Tel, Gnabry, Coman; Kane
We say: Heidenheim 2-4 Bayern Munich
Bayern have not lost to a Bundesliga debutant since a defeat to Energie Cottbus in 2000, also winning 17 of their last 18 against sides making their first appearance in the top flight.