Johannes Gutenberg invented the press in Mainz, and 550 years later Jürgen Klopp did the same.

The Liverpool manager is famed for his “gegenpress” philosophy, and his beliefs about how the game should be played were forged during his time in Mainz as both a player and manager. Klopp’s association with the club dates all the way back to 1990; all told, he spent more than two decades at the club. Tomorrow (Friday 23rd July), he comes face-to-face against his old team in a pre-season friendly — it’s a chance to reflect on how Mainz shaped the Jürgen Klopp we know today.

Klopp has actually returned to Mainz once already since joining Liverpool, another friendly affair as part of the German’s first pre-season with the club. He will be hoping for a better outcome: it was the most Alex Manninger ever had to do in a Liverpool shirt, picking the ball out of the net repeatedly in a 4-0 defeat. The team at Klopp’s disposal this time around will be better prepared, full of players who have been more thoroughly schooled in his methods: the very same methods that were first devised at Mainz.

The origin of Klopp’s pressing beliefs long predates his managerial career. As a player, the gangling striker-turned-defender worked under the tutelage of Wolfgang Frank in two spells between 1995 and 2000. He has since cited Frank many times as one of his principal coaching inspirations; indeed, when Klopp was appointed Mainz manager in 2001, a significant part of the logic was that an existing player would be best placed to replicate the system that has worked so well under Frank.

Of course, Klopp ultimately ended up surpassing Frank’s achievements, putting his own distinctive spin on the style that came to be known as gegenpressing. Even in the very early days, though, his talent for motivation was clear. Handed a potentially awkward situation whereby he was suddenly elevated above his long-time teammates, he guided the team to six wins from his first seven games to avoid relegation from the German second tier with a game in hand. The manager’s tactics have shaped how the modern game is played, but his man-management is a huge part of what makes him world class.

Perseverance was also embedded in Klopp at Mainz. Having avoided a potentially disastrous relegation, he soon set about making the club genuine promotion contenders. The team went close in both 2001/02 and 2002/03, falling just short on both occasions — the first was a record points tally for a non-promoted side, while the second saw promotion snatched away in stoppage time on the final day of the season. It would have broken lesser teams, but there is an uncanny resonance between Klopp’s football philosophies on and off the pitch: he finds a way to make sure players are ready to go, go and go again. Feeding off the heartbreak, his Mainz side finally made it to the promised land following the successful 2003/04 campaign.

It doesn’t take a genius to draw parallels to Klopp’s time at Liverpool. He has won the Champions League after losing the previous final. He ended the long wait for the Premier League after the cruelty of missing out with a points tally of 97 the season before. Such resilience was born in Mainz, along with the tactical ideas that have defined his career: Jürgen Klopp’s return is bound to be an emotional affair.