The club confirmed the Argentine icon will not join the rest of his team-mates on their tour of the USA after suffering a Grade 1 calf strain on Monday.
Ernesto Valverde and his contingent are travelling to Miami for a double-header against Italian giants Napoli.
Messi had only just returned to training from his extended summer break following Copa America efforts with Argentina.
Although a timescale for his return was not confirmed, the lack of training and the time out will now likely mean Messi is a doubt for Barca’s curtain raiser at Athletic Bilbao on Friday August 16.
Know more about Sport360 Application