They’ve been mates for more than 25 years.

Now German bosses David Wagner and Jurgen Klopp will go head to head when Huddersfield Town host Liverpool in a pre-season friendly.

The showdown for the Shankly Trophy will take place on Wednesday, July 20 (7.45).

The legendary Shankly, of course, looms large in the history of both clubs.

Now Wagner and Klopp are aiming to make their mark at the John Smith’s Stadium and Anfield respectively after being teammates at Mainz in the nineties and working together at Borussia Dortmund between 2011-15.

‘I am dark, he is light. He is tall, I am shorter. But our characters are very similar,” says Wagner, who at 44 is four years younger than the friend for whom he was best man.

Jurgen Klopp

“We like the same jokes and doing the same things.

“When we first met up at Mainz he was a striker and I was a striker. He was the main one when I signed from Eintracht Frankfurt in 1991.

“Then I took his place and he sat on the bench — this was the start of our relationship!

‘After a few months he dropped back as a defender, that made things easier for us!”

Former US international Wagner adds: We are very close and think the same way about football.

“To enjoy it is the most important thing, and I am also emotional during matches and training sessions too.

“It’s to show we are with the players, part of the team.

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‘I was Jurgen’s best man and did a speech at his wedding but I had drunk so much, I can’t remember what I said.

“It was at a restaurant in Mainz. In that situation it was very important to drink before I spoke!”

Klopp, who cut his managerial teeth at Mainz between 2001-08, took over as Liverpool boss in October.

There was talk of Wagner becoming a member of his Anfield coaching staff before he became Town head coach in November.

Klopp has already taken Liverpool to the finals of the Europa League and Capital One Cup as well as an eighth-place finish in the Premier League.

Town ended up 19th in the Championship.