Mats Hummels was standing with the referees for a long time after the final whistle, discussing and trying to convince, even though he knew that this 3-2 defeat against FC Bayern was inevitable. Perhaps at these moments the defender was looking for someone to be responsible for this bitter experience, and he knew that his arguments in the controversy with the referees would certainly be more convincing than attempts to explain his performance. Felix Zwayer and his assistants had made one of the unfortunate Hummels scenes with their penalty decision the key moment of the game. You could blame them for that.

With a little distance, however, the professional known as a self-critical person should also grapple with his own mistakes, with his form and maybe even with his future.

Because the 32-year-old world champion from 2014 is currently no longer very much help for his team in many moments.

“It wasn't always the best football,” said coach Marco Rose, and he certainly meant the mistakes in defense and in the build-up of the game in which Hummels was involved.

Whereby these weaknesses did not come as a complete surprise.

There have already been a number of groundbreaking situations this season in which Hummels was involved either as a producer of mistakes or as a unlucky person.

It's not always that easy to separate them.

The completely unjustified red card in the 1: 3 against Ajax Amsterdam was such a moment.

Just like the handball on Saturday, which led to the penalty and the winning goal for Bayern.

His involvement in the second Munich goal was not a clear mistake either, he was unluckily shot by his colleague Raphael Guerreiro, whereupon Kingsley Coman came to the ball and scored.

"This is due to the age"

But at some point the wise Thomas Müller said the beautiful sentence “Always happiness is ability!”.

Conversely, the accumulation of bad luck in Mats Hummels' game raises the question of whether he is currently good enough for top performances at the highest international level.

Especially since he also makes bad mistakes without the influence of coincidences.

Like against Munich before the 1-1 draw when he lost the ball under pressure at the center line. A failed chest pass almost resulted in another goal conceded in the first half. Such situations can be found in almost every game of the past few weeks, the balance between willingness to take risks and error rate no longer fits at Hummels. Karl-Heinz Rummenigge, long-time CEO of FC Bayern, said on Sunday on Bild-TV: "It is well known that Mats has problems when he has to go into running duels - this is due to his age."

Hummels struggles with permanent knee problems, he seldom hits his once legendary vertical balls with the outside instep, and he prefers to leave the flat passes in the front midfield areas to Akanji, because he is simply more reliable. And when Hummels leaves his defensive chain to defend forward, he can be outplayed more and more often. Upstairs in the stands was Hansi Flick, who must also notice that Hummels is currently not playing in the form of a national player. The national coach can cope with that, he has alternatives. On the other hand, Hummels' weaknesses must be worrying for Dortmund coach Rose.

Because at BVB there is a lack of high-class substitutes.

Marin Pongracic has not yet really arrived in Dortmund, and the highly talented Dan-Axel Zagadou is injured so often that his development has recently stagnated.

But it would be difficult anyway to put Hummels on the bench because his services to BVB are so great and his mostly clever words carry so much weight.

When the Dortmund team retired in Lisbon at the end of November without their suspended leader, there was also no reassuring influence from the back row that emanates from this experienced professional.

So Dortmund have to deal with the deficits of this player for the time being.

But if Hummels wants to be one of the strongest players in a team that can become German champions or win the Europa League, he needs a longer period in top form.