Bayern Munich are out to re-assert their authority in the Bundesliga at Stuttgart on Sunday, with three rivals poised to knock them off top spot if they falter.
After hammering Werder Bremen 4-1 last weekend, Bayern are top by a point and need to win at mid-table Stuttgart to keep their rivals at bay with two weekends left before the winter break starts.
Defending champions Borussia Dortmund are at home to strugglers Kaiserslautern on Sunday, while third-placed Borussia Moenchengladbach are at bottom side Augsburg on Saturday.
Both Bayern's main rivals should pick up the points to keep the pressure on, while fourth-placed Schalke could provisionally draw level on points with the leaders if they win at Hertha Berlin on Friday.
"It's especially important we get back to winning again immediately," urged Munich's Thomas Mueller ahead of the trip to Stuttgart, having sat out Bayern's Champions League defeat at Manchester City on Wednesday with illness.
Mueller and striker Mario Gomez, the league's top scorer, are both struggling with flu, while Dutch winger Arjen Robben and Germany midfielder Toni Kroos missed the 2-0 defeat in Manchester for the same reason.
Coach Jupp Heynckes is waiting on the fitness of the quartet to decide who will face a Stuttgart team who are in erratic form.
Dutch defender Khalid Boulahrouz has been ruled out for the home side after tearing a hip tendon.
"There is no right time for an injury, but just before the winter break is particularly annoying," said the 29-year-old on Stuttgart's website.
Bundesliga dark-horses Gladbach will be without injured winger Marco Reus at Augsburg as he continues his recovery from a broken toe.
The 22-year-old has scored 10 goals in 14 matches, but broke the little toe on his left foot a fortnight ago and is still not able to run without pain, forcing him to miss last Saturday's 1-1 draw with Dortmund.
Augsburg are bottom of the table with 11 points from 15 games, while Gladbach are the surprise package of the Bundesliga this season, having become title contenders despite only narrowly avoiding relegation in May.
Dortmund will be without captain Sebastian Kehl at Kaiserslautern after he took a heavy kick in the face during Tuesday's 3-2 Champions League defeat at home to Marseille, which left him in hospital.
Although the defensive midfielder did not break any bones, he admitted his bruised face made it look like he had "been in a fight against both of the (world champion) Klitschko brothers at the same time".
Kehl is the third key player Dortmund have lost to a facial injury in the last four weeks, after defender Neven Subotic broke a cheek bone and midfielder Sven Bender broke his jaw in two places.
Hertha Berlin v Schalke 04
Saturday (1430GMT unless otherwise stated):
Werder Bremen v VfL Wolfsburg, Mainz 05 v Hamburg, Nuremberg v Hoffenheim, Cologne v Freiburg, Augsburg v Borussia Moenchengladbach, Hanover 96 v Bayer Leverkusen (1730GMT)
Borussia Dortmund v Kaiserslautern (1430GMT), VfB Stuttgart v Bayern Munich (1630GMT)