WATCH: Jurgen Klopp Joins In With Surprised Liverpool Fans for Rendition of 'Allez, Allez, Allez'

Friday night saw Liverpool boss Jurgen Klopp surprise a group of fans at a club led event in Michigan - on the eve of the Reds' pre-season friendly match against Premier League title rivals Manchester United. The German even stuck around to have a little singsong with musician Jamie Webster - who was performing his special BossNight set list.

It seemed a special moment. About 60 fans were in attendance at the team hotel in Ann Arbor, Michigan, an event set up for the Detroit Supporters Club. The likes of club legends Robbie Fowler and John Arne Riise had made an appearance for a Q&A session, but no one expected Klopp himself to rock up out of nowhere.

Embracing Webster, the Reds boss struck awe into his audience and as part of a very warm welcome, was quickly handed a pint of lager by a fan. As if his presence alone wasn't enough for the shocked fans, he even stuck around for Webster's rendition of 'Allez, Allez, Allez' - and was even caught singing on a few occasions.

However, before the song could kick off, a few words were uttered by the musician - thanking Klopp for what he's done for the club, in particular, last year's magnificent season...

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"It was being sung in Portugal (against Porto) on the concourse and we didn't know how far it was going to go or what happened," Webster began. "Me and my friends said to each other: that song will spur us on in Europe this season, that song could be the new Ring Of Fire. That song did so many things for us.

"So I went home, and I put it on the guitar, give it a bit of life and has been the song of last season, hasn't it?

"Jurgen, thanks very much, we owe you a lot."