In the wake of their shock defeat in Basel, Bayern Munich need to beat title rivals Schalke 04 on Sunday to ease their growing crisis and bridge the gap behind German league leaders Dortmund.
Having already knocked Manchester United out of the Champions League, FC Basel added Bayern's scalp on Wednesday as a late goal sealed their 1-0 win in the Round of 16 first-leg with the return leg in Munich in a fortnight.
The Bavarians have claimed just three wins in their last seven games and slipped from top to third in the German league, while their Champions League progress this season is far from assured.
The arrival of fourth-placed Schalke, who are just a point behind Bayern, will test fragile confidence and the hosts need a good result plus a strong performance at Munich's Allianz Arena.
"We are in a very difficult period, you can see that in every single player," admitted striker Mario Gomez with Munich four points behind Dortmund.
"Everyone is carrying the burden."
Schalke are in form following their 4-0 hammering of Wolfsburg last Sunday, while Bayern's goalless draw at Freiburg last Saturday was a precursor to what followed in Basel.
Bayern's season hinges on the next few weeks.
On consecutive weekends, they face Schalke and Leverkusen, who are both in the Bundesliga's top six, then the Champions League return leg against Basel in Munich on March 13 followed by the German Cup semi-final at Moenchengladbach on March 23.
"We've arrived at a very important moment in Bayern Munich's season," chairman Karl-Heinz Rummenigge has told his players.
"I have certain concerns and points to ponder: what has basically happened between Christmas and now?
"You need to be alert, you have to be angry."
The visit of Schalke pits the league's joint top scorers against each other with both Bayern's Gomez and Schalke's Dutch star Klaas-Jan Huntelaar having hit 18 goals in 21 league matches.
While Bayern are faltering, Dortmund are hunting their seventh straight win at home to Hanover.
With a three-point gap at the top, Dortmund are buoyed by the news Japan star Shinji Kagawa is poised to return just ten days after damaging ankle ligaments in training.
Dortmund coped with his absence by grinding out a 1-0 win at strugglers Hertha Berlin last weekend, but Kagawa has been in stellar form of late with four goals in four games before injury struck.
Dark horses Borussia Moenchengladbach host Hamburg on Friday night bidding to join Dortmund at the top of the German league on 49 points, although Lucien Favre's team have an inferior goal difference.
Gladbach have turned their fortunes around this season and after only avoiding relegation by winning the end of season play-off last May, they remain genuine title contenders.
Gladbach's success has been based on a rock-solid defence and Brazil defender Dante, who has played all-bar-one of their league games this season, has been linked to Bayern Munich.
Goalkeeper Marc-Andre ter Stegen sat out training in mid-week with a calf strain, but should play against mid-table Hamburg, as should striker Mike Hanke, who missed last Saturday's 2-1 win at Kaiserslautern with flu.
The only player definitely out is midfielder Patrick Herrmann, who broke his collarbone against Kaiserslautern and is out for up to eight weeks.
Borussia M'gladbach v Hamburg
Cologne v Bayer Leverkusen
VfB Stuttgart v Freiburg
Mainz 05 v Kaiserslautern
VfL Wolfsburg v Hoffenheim
Augsburg v Hertha Berlin
Werder Bremen v Nuremberg
Bayern Munich v Schalke 04
Borussia Dortmund v Hanover 96