BlueCo will be aware they made a huge mistake letting Enzo Maresca leave at the start of the year.
Chelsea agreed to mutually terminate the Italian's contract after conflicts arose behind the scenes, and Liam Rosenior's sacking after just 104 days in charge has highlighted just how much the 46-year-old has been missed.
Although Chelsea are searching for another permanent manager, Maresca is not in the running to return due to being the favourite to succeed Pep Guardiola at Manchester City.
And the magnitude of BlueCo's poor judgement has been laid bare by one of Maresca's former players.
Kiernan Dewsbury-Hall gives insight into Enzo Maresca's management style
Although Kiernan Dewsbury-Hall's time at Stamford Bridge didn't work out as he would've hoped, the former Leicester City man is enjoying a fantastic spell with Everton.
By his own admission, he still has a soft spot for the Blues, though, and looks back even more fondly on his time spent working under Maresca.
Speaking live on Sky Sports' Monday Night Football in the build up to Manchester United vs. Brentford, the 26-year-old midfielder offered an insight into the Italian's management and coaching style.
"Relentless. He plays football like it’s chess. If you ever speak to him, he’s a massive Chelsea fan. I like Chelsea myself, so I can resonate with him on that.
But, it’s so tactical, methods to everything, there’s combinations, you have to be in the right position. And I got so used to that, I got so used to understanding exactly where to be on the pitch. I knew there would be people there, there and there.
And I really enjoyed it, because I feel like I’m a technical player, and some players might like that, but some players might like a bit more freedom. But, it got me in positions to score goals, it got me in positions to record assists, and everybody knows in this day and age, you are judged on that more."
Although nothing Chelsea didn't already know, Dewsbury-Hall's comments will still sting, especially when fans remember what could have been.
BlueCo cannot afford to get next manager appointment wrong
BlueCo's search for their fifth permanent appointment in just four years proves just how much instability there has been since they took over from Roman Abramovich.
While the US ownership look to be aiming high with the likes of Andoni Iraola and Xabi Alonso in contention, there is huge uncertainty over which manager they'll go for, or if they'll even take the job.
Either way, with Champions League qualification slipping out of reach, BlueCo absolutely must get it right in the summer or risk the team drifting further away from the Premier League's top clubs.
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