He’s right. When Dortmund won the Champions League in 1997, they finished third in the Bundesliga – eight points behind Bayern. In 2013, the gap was 25 points. Conversely, when Klopp won back-to-back titles in 2011 and 2012, they were knocked out of Europe in the group stage.

This season, Terzic led Dortmund successfully through a daunting group, including home and away wins over Newcastle United, victory over AC Milan in the San Siro and a draw with Paris St-Germain.

Their European excellence continued into the knockout stages, now boosted by two Premier League loanees – Chelsea’s Ian Maatsen and, of course, Manchester United winger Jadon Sancho, back at the club where he’d made his breakthrough.

Sancho’s final game for Dortmund before joining United had been that 2021 German Cup final under Terzic, whose undisputed man-management qualities are again benefitting the Londoner after a difficult time in Manchester.

“Jadon and I both know that he’s not yet at his maximum level,” said Terzic in April. “But we knew that and took it into account when we brought him back here. We see how hard he’s working and we’re sure he’ll hit top form again soon.”

Which is exactly what Sancho did, producing a man-of-the-match display in the Champions League semi-final first leg against PSG and setting Dortmund on course for the final.

At full-time after the second leg in Paris, Terzic disappeared into the jubilant mob of Dortmund fans at the front of the away end. Those same fans who had picked him up on the final day of last season against Mainz.

“This is why we do it,” he said afterwards. “We’d hoped for such scenes last season. Unfortunately, it didn’t go as planned but our fans were there for us. Today, we could give them a little bit back.”

Terzic and Dortmund remain a mystery. “Who can work out Jeckyll and Hyde Dortmund?” asked tabloid BILD, stating: “Terzic is unsackable now.”

And for local broadcaster WDR, Dortmund’s progression to the final is already “the triumph of a beleaguered coach”.

And what about the fans? Sitting on the train to Dortmund’s last game of the season, one BVB supporter admitted he “would have sacked him at Christmas, but how can you criticise a coach who’s taken us to the Champions League final?”

The mixed feelings were replicated around the beer stands under the Südtribüne. “He’s brilliant, he’s one of us,” added another. “But as a coach…?”

Terzic was a fan at the Olympiastadion in 2012. He was a fan at Wembley in 2013. As he said, however, “those days are over.”

Now, he wants to be seen as Terzic, the Borussia Dortmund head coach.

“Is there anyone who works in football who wasn’t once a fan?” he asked, rhetorically.

“Whether journalist, steward or press officer, we all fell in love with football as fans and we all had a team which we loved and supported. My path as a fan led to me becoming head coach of Borussia Dortmund. I’m very happy about that. And very proud.”

And whatever happens at Wembley, he’s sure to remain what the banner at the Olympiastadion called for – a Dortmund hero.