Dortmund won over the hearts and minds of the continent’s fans with an exhilarating run to last season’s Champions League final, where the club was defeated by a late winner from Bundesliga rival Bayern Munich.
Despite routing Real Madrid 4-1 in the first leg of the semifinal this year, Dortmund coach Klopp claims his side will keep on improving.
Speaking to UEFA.com, Klopp said: “We haven't reached our peak in terms of performance yet, but if we look at our results last season then we almost achieved it.
“We still don't have a clue how well the team can play, we still have to show that.”
The 46-year-old has instigated an incredible turnaround since taking over at the Signal Iduna Park in the summer of 2008.
Klopp cut his managerial teeth at Mainz before joining Dortmund and in the five subsequent seasons the club has won two Bundesliga titles and the 2012 DFB Pokal. Klopp has also been awarded coach of the year in Germany twice.
However, Klopp insists that he isn't performing magic.
"I’m no magician," he said. “We cannot make good players out of bad players. We need to recognise the potential in the right players, try to develop it to turn it into skills with the help of everyone involved. That's how you can find success.
“Generally I think we can make a team better with the way we work, with the way we train.”
Dortmund is grouped alongside Arsenal, Marseille and Napoli in Group F, but Klopp was reluctant to predict a similar European adventure to last year and admits his side struck was a bit lucky en route to Wembley.
“You can only reach the final by also being lucky in some situations. No team makes it to the final just because they're the best and strongest team," he continued. “We were certainly not the best team and therefore we needed a bit more luck. You also need a big heart, great desire, and then we can make it a long way, but we might also be knocked out in the group stage.
“In the Champions League the quality of the other teams is just too high. It would have been crazy if we had won the Champions League last season. Only a few lads thought they would become Bundesliga players, and five years later they became domestic champions twice and won the German Cup once. And to have then become Champions League winners, that would have been an incredible story.”
Certainly Klopp’s Dortmund has become an incredible story regardless, and the coach explained how managing the club requires much more than just on-field success.
“You need a playing philosophy that reflects your mentality, that reflects the club, that gives a direction to follow," he said. “That means taking the passion to its limits. Borussia Dortmund don't just play for a result, Borussia Dortmund means an experience.”
Follow GOAL.COM on