Painful experiences from Munich, Madrid, Paris, and Barcelona would typically make Celtic approach a Champions League trip to Borussia Dortmund with some apprehension. However, the striking confidence displayed by Brendan Rodgers indicates a team that has found its rhythm well before the seasons change. Rodgers isn't promising a monumental victory against last season's Champions League finalists, but he clearly believes such an outcome is within reach.

"For us, it's about taking our game to the next level," Rodgers said. "I think our performance over the last six to seven months has been steadily improving. Now, we've reached this level and we're fully aware of the challenge. We're up against a team that is competing at the highest echelons of elite football. But for us, whether it's domestically or in this competition, our goal is to be a tough team to play against, both with and without the ball. That's what we aim to achieve. I'm not seeking perfection; I just want us to be extremely difficult to play against and give our all.

Bring our game, which involves pressing, fighting, and running. We know that quality can sometimes push us back, and it's crucial to have resilience in those moments. But we also know that our game can hurt teams, with our footballing skills and speed. So, I'm genuinely excited to see that."

Rodgers is content to promote the idea that he's managing a Celtic side that can be a different entity in Europe compared to the one that has faced distressing nights against top European teams over the past decade. "Mindset, belief, and experience," he said, describing the transformation. "We've also added players who provide us with something crucial in key areas of the pitch."

Indeed, Celtic arrived in Germany on Monday having won all nine of their matches this season, scoring 33 goals and conceding just four. The most significant fixture was not the 3-0 victory over Rangers, but the 5-1 thrashing of Slovan Bratislava to kick off their Champions League campaign.

"I think we're in a great place," Rodgers said. "I trace it back to pre-season. The games we played then, we focused on certain aspects of how we wanted to perform at this level. I was very pleased with what I saw, and that has continued throughout. So, coming here is a great opportunity for us, and I'm excited about it."

Celtic will, however, be without their influential center-back Cameron Carter-Vickers, who stayed in Glasgow for treatment on a toe injury. Anyone hoping for sparks to fly between Rodgers and his counterpart at Dortmund, Nuri Sahin, will be disappointed. Sahin cut short a loan spell at Liverpool, then managed by Rodgers, in 2012 and was less than complimentary about the Northern Irishman upon leaving Anfield. His career was revitalized by Jürgen Klopp at Dortmund.

Sahin, though, has no interest in dwelling on the past negatively. "I liked his training sessions; they were very interesting," said the former Turkey international about Rodgers. "I was already taking notes for my own coaching career."

"I don't remember what I said back then when I was young, but the only issue was that I played in a different position than I usually did. The problem for me was that Steven Gerrard played in my position. So, I had to adjust, and that was the only thing."

"Everything else, I really enjoyed my time at Liverpool and also under Brendan. I enjoyed every training session with him; his ideas were very possession-oriented, playing in the opposition's half. I can only say good things about him and my time there."

Rodgers described Sahin as "a good guy." "He loved his football, trained very well, was super professional, and of course, he left Liverpool and went back to Dortmund, and I followed his career from there. It'll be really good to see him as he takes his first steps as a manager. He'll now understand the challenges of managing and all the various aspects that come with being a manager. So, I'm looking forward to seeing him."

Rodgers left the distinct impression that he believes he can achieve more than just that.