Barcelona have confirmed that Lionel Messi has suffered a calf injury and will not travel to the United States for their two friendlies against Napoli.
Messi was on the bench as Barca beat Arsenal on penalties in the Joan Gamper trophy, but did not come on as a substitute.
He is now a doubt for the Catalan giants' first game of the season against Athletic Bilbao next Friday.
"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," an official statement read.