The sight of Mats Hummels striving, struggling and ultimately failing to provide an explanation for Bayern Munich's weekend loss at TSG Hoffenheim was an arresting one.

He was being interviewed straight after the game by Bundesliga.com, with little time to collect his thoughts, but the look on his face was a puzzled one—searching for why his team, who so often have the answer, were left without one in Sinsheim.

"I think we were the better team today for a big portion of the game," Hummels said. In terms of the numbers, he had a point. Bayern had a virtual monopoly on possession (72 per cent), and had 23 efforts on goal compared to the home side’s six.

Yet, as the Germany international acknowledged straight afterwards, it's all about efficiency. Bayern, usually synonymous with that quality, were sorely lacking in it.

That was the case again on Tuesday night as they returned to UEFA Champions League action.

Ostensibly, it was the first stage of recovery as Bayern swept aside RSC Anderlecht, as expected, 3-0, and there were some promising aspects to the success. Jerome Boateng's comeback, for one, having been out since a bad thigh muscle injury in the final game of last season. He even laid on the final goal for Joshua Kimmich. There was a full debut for James Rodriguez, too.

There was also, however, a feeling of an unfulfilled evening of promise, especially after the visitors' Sven Kums was red-carded for a foul on Robert Lewandowski 11 minutes in, with the redoubtable Poland striker scoring the resulting penalty.

The mind flitted back to March 2015, and the last-16 second-leg match against Shakhtar Donetsk—a better side than Anderlecht by any measure of comparison.

In that case, Shakhtar's Olexandr Kucher was sent off even earlier (his third-minute red was the quickest in competition history). And after Thomas Muller scored from the spot, Bayern went on a spree, with Pep Guardiola's side quite merciless on the Ukrainian champions, going on to win 7-0.

Not only was the Allianz Arena not treated to an equally brutal display on Tuesday, there was rarely the suggestion it would be.

Again, there was little of the zip and definition on the ball that we have come to expect of Bayern at their best. "After we went 1-0 up," Arjen Robben said after the game (via L'Equipe, in French), "we played like we were 5-0 up. Our fans deserve more than that."

Those words, and the parallel with that match against Shakhtar, are not the only implicit criticisms of Carlo Ancelotti.

Much of the current perception of the coach suffers by comparison with the reign of his predecessor. Guardiola examined every detail. He was, as Marti Perarnau noted in his excellent book, Pep Confidential, a man who chased his own tail, locking himself in his office for three days to study every aspect of the opposition before playing modest Mainz.

Ancelotti is the exact opposite; more laissez-faire, he treats his players as adults and expects them to behave as such. Let's not pretend, either, that shunning micro-management hasn't or doesn't work at the world's biggest clubs, when faced with a dressing room of superstars.

Vicente del Bosque won a brace of Champions Leagues managing Real Madrid that way. Today, Zinedine Zidane—who worked closely with Ancelotti on the way to Real's 2014 win in the competition—is inclined towards less is more, rather than poring over every possibility in the way some of his celebrated peers do.

The problem for Bayern is not a new one, having existed since the beginning of last season. It's the lack of that magic word: intensity.

Bayern's players were pushed every inch of the way under Guardiola. Sometimes it was too much. The images of the coach making his points, forcefully, to an intimidated-looking Kimmich on the pitch immediately after a draw at Dortmund in March last year are this feeling made flesh.

There is little doubt either that some of the players were sick of this by the end, including Muller and Franck Ribery.

The leap between Guardiola's approach and Ancelotti's credo, though, has just been too much. After a lot of average performances last season—despite winning the Bundesliga by 15 points, Bayern often underwhelmed—there was a hope we might see FC Hollywood in 4K this season.

The realisation that it's not the case—and that it probably won't be, going forward—has changed the atmosphere. A poor pre-season set the tone, and wins in all the games apart from the one at Hoffenheim have done little to reverse the mood.

Take Ribery tearing off and throwing his shirt at the bench as he was substituted late in the Anderlecht game. How this is viewed is different with Bayern in a good place (he's passionate, and it's proof of his competitive instinct) and in a not-so-good place (he's angry, indicative of disquiet at the club and of a loss of faith in the coach).

The thought occurred here that maybe Ribery was almost trying to engineer feeling when it seems there's not enough. Interestingly, Robben talked about the need for "passion" in his post-match comments.

There was much to admire in Ancelotti's intentions for the Anderlecht game. With Robben, Ribery and James lined up in support of Lewandowski and the two nominal sitting midfielders, Thiago Alacantara (the scorer of the second goal) and Corentin Tolisso—both far from dedicated defensive players—this was an ambitious choice.

Yet, the fluidity was lacking. It was hard to escape the impression that Bayern are just a little undercoached at present.

With this in mind, Bayern—or Ancelotti—picked the worst possible time to be turned over by Hoffenheim, with the shadow of Julian Nagelsmann's ascension hanging high and the growing feeling that it's a matter of when, not if, he takes over at Sabener Strasse.

This was before the Eurosport interview emerged of Nagelsmann openly admitting, for the first time, that he would like the job (via journalist Archie Rhind-Tutt):

Also at the weekend, former Bayern player Mario Basler even claimed on Sport1 (via ESPN FC) to have it on good authority that Ancelotti had agreed to take a job in China from January—something the Italian later called "a joke."

The Italian dealt with the matter with dignity, just as he did with Ribery's strop and the Nagelsmann question in the aftermath of the Anderlecht game (via ESPN FC), as he always does.

Bayern will survive, just as they will get over Lewandowski's complaints about the club not spending heavily enough in the summer transfer window in an interview with Der Spiegel (h/t Goal).

This, and the angry responses by former players such as Stefan Effenberg, is the essence of Bayern—outspoken, argumentative and self-governing. In fact, this is why it felt as though a relatively hands-off coach like Ancelotti would be such a great choice.

The problem has been that after the intense aesthetic peaks reached by Guardiola, it hasn't been enough. It may still be enough to clinch the Bundesliga for a record sixth successive seasons, with Leipzig now competing on two fronts and Dortmund still something of an unknown quantity.

Yet, in a season of such intense competition in the Champions League, the chances of Ancelotti doing what he was brought to Bayern for—to bring that trophy back—appear to be in the process of receding.