Jurgen Klopp took on a big rebuilding job when he joined Liverpool back in October 2015.

Unlike Arne Slot, who walked into a team ready to compete at the highest level, Klopp had to bide his time and build the team that would become English and European champions.

The clearout started in summer of 2016, when Klopp moved on several players who would not be part of his Liverpool rejuvenation.

Welsh midfielder Joe Allen was one of those to get the boot, shipped off to join Stoke City for £13m.

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It was a decent fee for Liverpool, who had paid around £15m to sign him from Swansea City four years before.

A key player under Brendan Rodgers, Allen had become side lined a little when Klopp took the helm.

However, a re-emergence at the back end of the 2015/16 campaign followed by a good start at Stoke had reporters questioning why Klopp let him go.

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Allen was a decent little player for Liverpool.

According to Klopp, though, his sale was simply a case of the player being keen to get more game time elsewhere.

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“Do we miss Joe Allen?

He’s a nice guy, unbelievably strong player,” Klopp said via the Liverpool ECHO in December 2016.

Sometimes injuries were the reason.”

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“We all knew about his quality.

It’s about having one option more or not.”

Nine years on from his slightly disappointing Liverpool departure, Allen has now announced his retirement from football.

Back at Swansea City – where Liverpool signed him from initially – the 35-year-old will finish his playing career at the end of the season.

“It’s been a very difficult decision but one that, it goes without saying, I have given an awful lot of thought to,” Allen told swanseacity.com after announcing his retirement on Friday.

“I am 35 now, and with what I have put my body through with the injuries and the level I can reach at the moment, it feels like the right time to call time on my career.”

Listening to Klopp’s words, it sounds possible that Allen could have stayed at Liverpool if he’d been willing to accept a more bit-part role under the German.