ROMEO LAVIA left Southampton with bags of potential and returns having realised it in rapid time.
The Belgian, and Chelsea, may have had to wait a year due to injury but now he is fit there is no question that the youngster is firing.
In just eight Premier League appearances for the Blues this season, there are few in west London who are in doubt about just how far their new midfield metronome could go.
Everyone at Southampton, who signed the midfielder from Manchester City in 2022, knew they had a talent on their hands who may not be around long.
In fact, if Chelsea had got their way he would only have been at St. Mary's for a matter of weeks - with the Blues seeing a £50million bid rejected less than three months after he had joined Saints.
They got their man a year later and, after another season of injury frustration during which Lavia managed just 32 minutes of football, are now reaping the rewards.
Chelsea's £206m midfield duo of Moises Caicedo and Enzo Fernandez drastically under-performed last season, looking lost at times.
But the introduction of Lavia, and his ability to stay fit, has settled them and provided the platform for both to shine.
Initially Fernandez was forced out of the side in favour of Lavia but has returned in recent weeks and has two goals in as many games.
All three of Lavia, Caicedo and Fernandez started together as Chelsea swept Aston Villa aside on Sunday, though Enzo Maresca had dropped the 20-year-old for the game at Leicester beforehand.
A challenge to show there is still more to come.
He said: "I trust him for sure, but he didn't play at Leicester away, so two games ago he was on the bench.
"I said then just because he was on the bench it doesn't mean he is not doing well, it was because the game plan changed for that game. We are completely happy about Romeo.
"Romeo is doing very good with us but because I know him very well he can do much better.
"He is a top player but he is only 20 and still has to improve on many things."
Lavia outstrips both of his teammates when it comes to passing accuracy, including in the opposition half, and interceptions.
The former Man City man has always considered himself best as a holding midfielder and that solid foundation gives any partner alongside him the confidence to push on.
Teammates at Southampton quickly realised that, despite being 18, Lavia's vision and understanding of the game matched up to those with hundreds of Premier League appearances.
Senior figures training alongside him noted how eager he was to learn, looking to pick the brains of anyone he could borrow from.
And that is some cast list for such a short career, starting with Pep Guardiola, Kevin de Bruyne and Rodri in Manchester, where he also first met Maresca working in the academy.
The talent has always been there, but being able to display it had been a challenge until now.
As well as playing in a relegation side at Southampton, injury problems were a constant on the south coast.
Theo Walcott, who played alongside him, revealed after his move to Chelsea that he "trained too much" for a young player, while Lavia has admitted that it took him time to understand his body.
Speaking to SunSport in the summer, Lavia said: "You're young and you want to play.
"You're getting to know your body as well, which is sometimes unfair because you feel like you're doing everything right to get back but nature sometimes decides in a different way.
"It was just about understanding that and growing as a person. It was frustrating but it was more in the head, and now it has helped me."
During that time Lavia leaned on compatriot and Chelsea great Eden Hazard for advice, while also trying to stay as close and connected to his new teammates at their Cobham training base even though he could not join in the sessions.
For someone who sees themselves as a leader within any group, it was a challenging year but one which, undoubtedly, will have long term benefits.