Messi is looking to end his relationship with the Catalan giants after reportedly growing frustrated with the club's board and president Josep Maria Bartomeu.
The first team players arrived in Barcelona on Sunday for testing ahead of pre-season on Monday.
Messi was scheduled to show up on Sunday morning, but a number of reports in Spain claim he did not show up as he insists he is no longer with the club.
Messi é aguardado neste momento no CT do Barcelona, mas não irá fazer os exames da pré-temporada.
Não vai porque já enviou um comunicado oficial ao Barcelona dizendo que deixa de ser jogador do clube, apoiando-se na cláusula de rescisão unilateral.
The Argentine has since been linked with Manchester City and Paris Saint-Germain in recent weeks, with Pep Guardiola's side said to be the more likely destination.
The six-time Ballon d'Or winner has been heavily linked with Pep Guardiola's Manchester City in the past week, while Paris Saint-Germain could also be a possible destination.