Lionel Messi boycotted Barcelona's first pre-season training session on Monday, club sources have confirmed to AFP, as the striker upped the stakes in his battle to leave this summer.

After skipping coronavirus tests on Sunday, Messi was absent again from the club's Ciutat Esportiva training ground, where Ronald Koeman held a session at 5:30pm, his first since being appointed Barca coach. It appears increasingly likely Messi will try to force a transfer by refusing to play in La Liga next season, which begins on September 12. The 33-year-old and his lawyers believe that participating in Barcelona's pre-season programme would contradict their argument that Messi no longer belongs to the club.