Barcelona delivered their no. 10 to Ansu Fati, after the signing of Lionel Messi at Paris Saint-Germain.
The club officially confirmed this on Wednesday.
Barca had considered leaving the number unused for the 2021/2022 season. However, La Liga rules insist that first-team players must wear the numbers 1-25.
Ansu, who only returned to training after a nine-month injury hiatus, initially received the No.17 jersey for next season.
The forward has already worn numbers 22 and 33 since making his debut for the Catalans in 2019.
Messi has worn number 10 at Barca since 2008, having previously worn number 30 and number 19.
The Argentine striker inherited the number 10 jersey from Ronaldinho, with Juan Román Riquelme and Rivaldo among those who wore it before him.