Bayern Munich host 'bogey team' Mainz

In recent years Bayern have kick started Bundesliga campaigns with prolonged unbeaten streaks, the longest coming in 2013-14, when they didn't taste defeat until Matchday 29.

Yet Bayern's loss to Hoffenheim last weekendbroke that dominant trend. You would have to go back to the 2011-12 campaign to find a Bayern defeat so early in a season, when they fell to Borussia Mönchengladbach on the first matchday.

That was also, incidentally, the last time Bayern failed to claim the Bundesliga title, with Borussia Dortmund winning a second-consecutive championship under former coach Jürgen Klopp.

Is history repeating? Could this be a sign that Bayern's Bundesliga challengers may have a more even fight on their hands in the race for the top? The neutral fan may hope so - after all, the closest any team has come to Bayern in the past five campaigns was Wolfsburg in 2015-16 (trailing at season's end by 10 points).

Off-field drama casting shadow

On top of that early setback, Bayern and coach Ancelotti are dealing with perceived player discontent.

First, Thomas Müller reacted poorly to being benched against Werder Bremenon Matchday 2, at a loss to what more Ancelotti expected from him. Next, Robert Lewandowski was quoted in Spiegel Online questioning Bayern's transfer policy.

And in Tuesday's Champions League win over Anderlecht,Franck Ribery threw his shirt to the ground after being substituted.

While each incident would be cast aside in isolation, together they have sent alarm bells ringing.

Ex-players have been vocal in the media, with former winger Mario Basler even claiming Ancelotti would be off in January, to China of all places. Whether unsubstantiated rumor or genuine assertion (Ancelotti labeled Basler's comments "a joke"), the speculation has reached an unsavory level for a club famed for its family-like atmosphere.

The off-field drama would also be easy to dismiss if performances on the pitch cast them as insignificant. Unfortunately for Ancelotti, however, the standard has been below-par so far in the new campaign.

On-field exploits below-par

Bayern cruised to a 3-1 win over Bayer Leverkusen, though looked vulnerable in defence in a game where Leverkusen perhaps should have converted more of their 15 shots.

Victory against Bremen on Matchday 2 looked less than certain until Robert Lewandowski broke the deadlock after 72 frustrating minutes. And that goal should not have stood, Lewandowski clearly offside and the subsequent absence of a video review one black eye for the VAR system.

Against Hoffenheim, of course, they were made to pay for early misses in front of goal and deservedly lost 2-0. And despite putting three unanswered goals past Anderlecht on Tuesday night, Bayern were less than convincing against 10 men.

Mainz test a chance to turn tide 

Improvement on the pitch is essential to calming the storm surrounding Bayern, and Ancelotti will look to Saturday's fixture against Mainz as the perfect tonic.

By losing their first two matches to Hannover and Stuttgart, two newly promoted sides, Mainz, under new coach Sandro Schwarz, looked be living up to the widespread preseason predictions that they would find themselves in a relegation battle However, a solid performance against Leverkusen brought relief and hope in the form of a 3-1 win.

A result against Bayern for a club still struggling for goals since Yunus Malli's departure (26 with the playmaker, 18 without last season) may seem fanciful, but Mainz' last two matches at the Allianz Arena have resulted in upsets.

At the back end of last season Mainz twice took the lead in a 2-2 draw, and in 2015-16 they pulled off a shock 2-1 win in the Bavarian capital. Another surprise result would give them a massive boost in their battle to overcome relegation odds.

For Bayern, a dominant display and convincing win on Saturday would be at least a minor step towards dispelling the off-field drama. Any slip-up, however, could see the rumor-mill spin ever faster.

Elsewhere on Matchday 4

-     High-flying Hannover look to continue their unbeaten start to the season against Hamburg. Andre Breitenreiter's newly promoted team look very much on track for Bundesliga survival.

-     Hoffenheim and Hertha Berlin return from Europa League duty to do battle. Hoffenheim have won three of their last four home matches against Hertha.

-     First-placed Dortmund host cellar-dwellers Cologne.

Matchday 4 Fixture List

Hanover vs. Hamburg (Friday, 8:30 p.m. CEST)

Werder Bremen vs. Schalke (Saturday, 3:30 p.m.)

Bayern Munich vs. Mainz

Eintracht Frankfurt vs. Augsburg

Stuttgart vs. Wolfsburg

RB Leipzig vs. Borussia Mönchengladbach (Saturday, 6:30 p.m.)

Hoffenheim vs. Hertha Berlin (Sunday, 1:30 p.m.)

Bayer Leverkusen vs. Freiburg (Sunday, 3:30 p.m.)

Dortmund vs Cologne (Sunday, 6:00 p.m.)