Colin Pascoe left the club as part of an end of season review, leaving Brendan Rodgers on the lookout for a replacement.
After an end of season review at Anfield between manager Brendan Rodgers and the club's owners Fenway Sports Group, Pascoe and Mike Marsh were among the backroom staff who left the club.
It came after a disappointing season at the club where the Reds missed out on Champions League qualification by finishing in sixth place and missing out on silverware.
The club backed manager Rodgers, but changes seemingly had to be made - and having worked with Pascoe for a lengthy part of his career, Allen is understandably disappointed to see him depart the club.
He is quoted by the BBC, saying: "I'm very disappointed, he's been someone who's been instrumental in my career," said Wales midfielder Allen, who came through the ranks at Swansea.
"We've worked together for... must be nine years, so he's been a huge part of my career, a massive help to me on a personal level.
"I'm very grateful for all the effort he's put in with me and it's certainly without someone like Pas's help I doubt I'd be playing at a club like Liverpool."
Undoubtedly, having worked for that amount of time with one person, it is going to have some kind of an effect on the player - as Allen has worked with Pascoe during his time at Swansea City as well as at Liverpool - where he became one of Rodgers' first signings.
It's difficult to know what kind of effect it will have on Allen's performance going forward, but it does show the need Rodgers has to appoint a worthy number two and first team coach.