Ansu Fati has agreed a new contract with Barcelona which includes a release clause that is set to reach 400 million euros ($A645m).
The 17-year-old academy product has burst into the first team at the Nou Camp this season, scoring two goals in 12 appearances, and became the youngest player to score for the club in LaLiga.
Fati's contract has been extended until June 30, 2022, with Barcelona confirming the Barcelona B team player's release clause has been increased from 100m euros ($A161m) to 170m euros ($A275m).
That figure is set to rise even further to 400m euros when he signs a professional contract with the first team.
Fati became the club's second-youngest ever debutant at 16 years and 298 days of age earlier this season and bagged his first professional goal six days later to became Barca's second youngest goalscorer and the third-youngest in La Liga history.
The Guinea-Bissau youngster paid tribute to Barcelona's famed La Masia academy.
"For me, La Masia is the best school in the world. They helped me from the first day I arrived and I am extremely grateful to everyone who works there" he told the Barcelona website.
"They are all spectacular. From the first day I have learned things from everyone. And they have also been there to support me through difficult times.
"Working every day with the best is a dream, and also a reward. From now onwards, what I have to do is keep working, even harder than ever, to keep getting chances and carry on enjoying myself. The rest will come after."
Australian Associated Press
