Barcelona's Argentine striker Lionel Messi will take over the No.10 shirt that was last worn by Brazil's Ronaldinho, who was transferred to AC Milan, the club said today.
The number 10 shirt is usually the privilege of the club's star player.
Messi, 21, has until now worn the No.19, which has not been assigned to any other player for next season.
Brazilian Daniel Alves, a pre-season signing, was given the No.20, formerly worn by Portugal's Deco, who has gone to Chelsea.
Messi has joined the Argentina national squad for the Olympics in Beijing and will miss the Catalan club's US tour.
The Argentina international has been at the centre of a tug of war between club and country with Barcelona trying to retain him for their Champions League qualifier tie in August.