Fikayo Tomori joined Chelsea as an eight-year-old and was part of the academy sides which won consecutive UEFA Youth League and FA Youth Cup titles between 2015 and 2016.
Following three consecutive loan spells at Brighton, Hull and Derby since 2017, Tomori has finally broken into the senior team at Stamford Bridge this season.
The centre-back made his first competitive start for Chelsea against Sheffield United on the last day of August, not that you could tell he was probably the least experienced player on the pitch.
However, the 21-year-old is first and foremost a defender and has practised marking some of the world’s best players during training sessions at Cobham.
Tomori came up against none other than Diego Costa in the 2015-16 season after then interim manager Guus Hiddink invited him to join in with the first team.
Despite being a teenager at the time, Tomori wasn’t dominated by the Spaniard.
In fact, he managed to break Costa’s nose.
Recollecting how it occurred, Tomori told Goal: “I was actually still in school and I didn’t know I had done it in training.
“It was an accident, we both went up for a header and I had to flick the ball backwards and he tried to score.
“He headed the back of my head and he broke his nose. I didn’t know I had done it until the next day when it was all over the papers.
“I was getting a lot of messages with people thinking I had meant to do it!
“It was mostly light-hearted, a lot of banter. I got back to school and people were asking about it. I was in year 10 or 11 and my mates had all seen it.
“It was all right. He didn’t kick me in training after that.”
Perhaps Diego might not have let Tomori off so lightly if the injury had forced him out of action.