According to a statement that was made available on the club’s official website, the South American teamed up with the rest of the squad in the USA where they are currently playing their pre-season matches.
He is now a major doubt for the season opener with Athletic Bilbao on August 18th.
In the statement, Barca said:
“First team player Leo Messi, who had returned from his summer break for training on Monday, withdrew from the session due to discomfort in his right leg.
“Tests carried out have diagnosed a Grade 1 calf strain for the Argentine.
“Messi will remain in Barcelona and will now not travel to the USA for the club’s tour. His availability to come back to action will be dictated by his recovery from the injury.”