Argentina will need to asses the damage to Lionel Messi's left hamstring before giving him the go-ahead to play in his country's World Cup qualifying matches.
La Albiceleste take on Uruguay on Friday before facing Venezuela the following Wednesday but may have to do without their talisman after he picked up the knock in Barcelona's 1-0 win at Athletic Bilbao on Sunday, although he played the entire match.
Tests performed on Monday that were approved by the FC Barcelona Medical Services and the Argentinean Football Association confirmed the injury, and his involvement in the upcoming games will depend on how it develops over the next few days.
Barcelona said in a statement: "Tests conducted have confirmed that Lionel Messi has a sore left adductor muscle. Both the Medical Services of FC Barcelona and the AFA have agreed on this report.
"The player will travel to Argentina to join the national team and the evolution of the discomfort will decide his availability to play in the games scheduled."
Messi, who was convinced by new Argentina boss Edgardo Bauza to come out of retirement, after missing a penalty in the penalty shootout loss to Chile in the Copa America Centenario final, will be hoping he is fit to play with Argentina currently third in the CONMEBOL qualification group after six matches behind Uruguay and Ecuador.
The top four teams qualify automatically for the World Cup, but the fifth-placed team will compete in a play-off tie.