Ronald Koeman’s men have been badly hit by injuries this season and losing Araujo, who has played every game this term, will be another blow.
“Tests carried out by the Uruguayan Football Association’s medical department have confirmed that first-teamer Ronald Araujo picked up a right hamstring injury during the match against Argentina,” Barca said in a statement.
The Catalan club are struggling on and off the pitch. They sit ninth in LaLiga and lost both their first two Champions League group games.
There had been good news for Barcelona on Monday, though, with the returns of Sergio Aguero and Ousmane Dembele to training.
Neither Argentina striker Aguero, who signed from Manchester City in the close-season, or France winger Dembele have played this campaign.