Senegalese winger says he rejected a move to Barcelona FC to join French side Stade Rennes.
Sarr, 19 completed a four-year deal with Rennes worth $20m (£15.2m) as he switched from rivals Metz.
He has disclosed after sealing the move that Barcelona were also interested in securing his side signature aside Rennnes.
“I could have gone to Spain and join the great Barcelona, but leaving Metz to join them was too early,” he said.
“I saw Rennes as a club that will help me progress and reach great heights.”
With just six caps for his country, Sarr has already been compared to former Rennes winger Ousmane Dembele, who now plays for Borussia Dortmund.
However the teenager is keen to create his own legacy.
“I still have to progress defensively, offensively with more flair, and be more decisive in my approach towards goal,” he added.
“With Christian Gourcuff [Rennes manager], I am convinced that I will succeed.”
Sarr helped AS Génération Foot progress from the second tier to the top flight of Senegalese League.
“I left Senegal a year ago to join Metz, I left my family there. I had to adapt to a new environment,” he explained
“Today I am happy, my parents are proud of me. I only count every day as a chance to make the best out of my profession.”