Born in Les Moulins Nice to Senegalese immigrant parents, Sarr’s footballing abilities were discovered by his hometown club OGC Nice where he spent 12 years polishing his craft and captaining the junior sides on his way to the first team.
He made his first team appearance for Nice in 2016, aged only 17, and grabbed a goal that would later make him the youngest ever player to score on his debut in Ligue 1.
That goal changed his life and he’s never looked back since then.
Sarr went on to sign a first-team contract, from which he moved his parents from the small council flat they were living in to a more spacious three-bedroom house on the French Riviera.
He would later be named as one of the best talents in Europe by CIES Football observatory.
At the end of a third season with Nice’s first team, it was clear the club and Sarr did not agree on a long term contract and he was left clubless before Chelsea came to his rescue.
“I was training on my own, training at home and just waiting,” he said.
“I had been almost six months without playing, and when my agent told me about this opportunity to come here to Chelsea, I was surprised and happy.
“I was always a positive person and I knew that at the end all I had to do was continue believing that I would make the right decision and it came for me.”
A slow start to life as a Chelsea player
Sarr was one of the early signings of Frank Lampard, with the French defender arriving just two days after the signing of Ben Chillwell, who had also arrived after the transfer ban was lifted.
Chelsea director Marina Granovskaia described Sarr as having “tremendous prospects” and the fact that he had run down his contract at Nice, made his move much more straight forward.
But unlike Hakim Ziyech, Ben Chilwell, Timo Werner and Kai Havertz, who all arrived at the club that summer, he was sent out on loan to FC Porto.
The defender quickly settled into life in Portugal and ended the 2020-21 season with 19 games, even if just five of those games came in the league.
The failed transfer that turned out to be blessing in disguise
After the season, it was clear Sarr did not fancy returning back to Portugal, and spent his summer training with the loan group at Cobham.
He would occasionally be called on to add up numbers in the first team, filling in for players who had extended holidays from participating in the Euros or due to Covid.
He played and impressed in pre-season games to build match fitness, even though secretly Thomas Tuchel was impressed with his attitude towards his work.
There was interest from clubs in the Championship and even German side Greuther Fürth made an offer to take him from Chelsea with an option to purchase, but talks broke down on transfer deadline day and Sarr was left in limbo.
With the transfer window closed, Tuchel was very honest with him and told him he would be welcomed into training, but was only going to be used as cover as he had planned his team already.
The French defender happily accepted and would be regularly one of the first to arrive at Cobham and one of the last to leave.
He would always have a smile on his face is an easy to approach person with no ego, a manager’s dream.
Despite not playing a lot, he’d been always ask questions of veterans Thiago Silva and Antonio Rudiger.
His first big chance came in the EFL Cup against Aston Villa, with Tuchel handing his debut at the club at Stamford Bridge.
Going from strength to strength
That debut at Stamford Bridge gave him so much confidence, and by the time was playing his first league game at Brentford, he had earned the trust of not only his colleagues but the fan base who were beginning to feel he had something to offer.
His cause has been aided by devastating injuries to Chilwell, Reece James and Andreas Christensen, but Sarr has earned his corn.
Against Tottenham on Thursday night his manager highlighted his improvement, and spoke about how his attitude and principles have helped him take any issues in his stride.
“He can play centre-back and in the left position of a back three,” Tuchel said after his impressive outing against Tottenham
"That’s where he is at the moment, he deserves to play. He has played well when he was needed.
“He is a good lad and takes whatever he gets and that is where we are with him.
“He just has to continue working hard and taking his opportunities.”
Chelsea will take on Premier League champions Manchester City, in what will be a repeat of last year’s Champions League final, and Sarr’s growing reputation is likely to give his manager something to think about when he’s picking his team.