The mood swing in Bad Ragaz is unmistakable. Ever since top striker Sébastien Haller was diagnosed with a tumor in his testicles on Monday, there has been dismay at Borussia Dortmund’s training camp – especially among the team-mates. “Football takes a backseat. We wish him to get well as soon as possible,” said Niklas Süle. The national player, who came from FC Bayern, was shocked when he heard about the diagnosis, like all teammates.

Borussia are currently trying to get back to work in the Swiss thermal resort, where they will be preparing for the coming season until Saturday. It was quite helpful that with Süle (26) and Nico Schlotterbeck (22), two other newcomers, from whom the Dortmunders have great promise, took the floor – and to draw attention back to football as best as possible tried.

The new centre-backs are intended to bring new self-confidence and a different mentality to the team, as was made clear in their first appearances in front of the press. “I didn’t come because I don’t believe that we can become champions,” said Süle, adopting an unusually bold tone for Dortmund. He was “convinced that we can do it,” said the ex-Munich native.

He also announced that he would apply for a leadership role in the team. “It’s hard to believe, but I’ll be 27 this year. I see it as my responsibility, I’m one of the more experienced and I want to lead the way – with performance and also in the media when things don’t go well,” he explained.

With this attitude, Süle corresponds exactly to what the new sports director Seabstian Kehl and the new coach Edin Terzic demand from the players of the runners-up: They should become mentally more robust, no longer (like in the past season) duck away in the face of resistance.

Schlotterbeck also wants to conform to this image. The former Freiburg player, like Süle a current national player, also has big plans for BVB. “My longing for titles is very great,” he said, recalling how much he had suffered after losing to RB Leipzig in the cup final with his former club. It took him a few days to process it.

He sees chances of winning a title in Dortmund – although he is also aware that the competition in the BVB defense will be very fierce. With Süle, Schlotterbeck, Mats Hummels (33) and Manuel Akanji (27), who is willing to emigrate, there are currently four prominent central defenders under contract – but usually only two of them can play.

“It remains to be seen whether I’m a challenger or a regular player,” explained Schlotterbeck. However, he will never appear humble: “I want to give my ambition to the team.” He could learn a lot from Süle and Hummels. “They have shown top performances over the years,” says Schlotterbeck: “But I also believe that the two can also learn a little from me.” What is that exactly? “My style. I’m my own type, I approach the game with a lot of self-confidence and like to take on responsibility.”

Terzic will take good note of such a statement. In the days at Bad Ragaz, the coach tried very hard to keep up the competitive pressure and create a performance-enhancing atmosphere. This was also clearly visible in several training sessions. The players gave nothing. “It’s normal for the intensity to be high during preparation, but I didn’t expect it to be so brutally high,” said Schlotterbeck. This is the consequence when many top players fight for their places.

Süle and Schlottebeck should – whichever personnel constellation Terzic decides to use at the start of the season – help BVB become more defensively stable and reduce the number of goals conceded. “We’re very well manned in central defence,” said Süle. With Schlotterbeck he has already “sniffed” with the national team, and he also knows Hummels well.

However, the key to BVB having a good season and actually being able to annoy Bayern is to bring the mentality conjured up in Bad Ragaz onto the pitch. “Intense and dominant football” is necessary, believes Schlotterbeck. “If you don’t call up top performances in every training session, in every game, you will pay for it,” he explained. The entire team is required. If these guidelines were to be implemented, then the chances of winning titles would appear more realistic again. “We will do a lot for it – but you won’t be successful just by chatting,” said Süle.

In any case, Süle and Schlotterbeck will ensure a new dynamic within the squad. This can already be seen in the preparation. “We’re a good bunch, with many different characters,” says Süle. He was still there for a long time, “but I didn’t see a mentality problem here.”