Atletico Madrid midfielder De Paul sidelined with leg injury
De Paul came off with muscle discomfort late in Argentina's World Cup qualifying win against Bolivia on Tuesday and missed training with his club on his return to Madrid.
"De Paul has already started to receive physical therapy sessions and will carry out rehabilitation work in the gym," Atletico said in a statement on Friday.
"The evolution of his injury will determine his return to work with the group."
Spanish media reported that he will also miss Atletico's Champions League opener at Lazio on Tuesday but is expected to be fit for next week's derby at home to Real Madrid.
De Paul's absence for Diego Simeone's side comes on top of injuries keeping out Reinildo Mandava, Caglar Soyuncu, Koke and Memphis Depay.