The £166m teenager has unveiled as a Paris St-Germain player today following his monster move from Monaco.
But Chelsea took a look at the Frenchman years ago when he was playing for amateur side AS Bondy.
Mbappe played alongside the likes of Tammy Abrahams and Jeremie Boga in a friendly game for the Chelsea academy.
And those in charge at Stamford Bridge must be kicking themselves following Mbappe's sensational rise to fame.
He said: "It was a wonderful experience.
"Chelsea was the first great club, the first big club, that I went to visit.
“So it was a real discovery for me.
"I was coming from my grassroots, amateur club. It was a whole new world.
“Of course I had an idea what a great football club was like but I was really impressed by the working culture and the mentality of wanting to be better day-in, day-out.
"And visiting this infrastructure helped me, actually, with my development.
“I saw things differently because up until then I had just a French mentality and after that I could pick what was positive in other mentalities and build my own."
