Argentina have confirmed that striker Sergio Aguero damaged his left hamstring in the 2-0 World Cup qualifying defeat to Ecuador on Thursday.
The Manchester City star was replaced by Carlos Tevez just 22 minutes into the contest after pulling up in clear discomfort when chasing down Gabriel Achilier in the attacking third.
The Argentine Football Association (AFA) have since confirmed that the 27-year-old has suffered an injury to the femoral biceps of his left leg.
Head coach Gerardo Martino later revealed that City boss Manuel Pellegrini had concerns about Aguero's fitness prior to the match, though he said the latest muscle damage appears to be an unrelated problem.
"It's true that Aguero was carrying a problem," he said. "Pellegrini took him off after 60, 65 minutes in his last game [against Newcastle United].
"But without having spoken in depth with the doctor, I'd venture to say the injury from today is not in the same place."
City and Argentina team-mate Nicolas Otamendi later revealed Aguero had been in tears in the dressing-room following the game.
Aguero is now unlikely to face Paraguay next week for his national team and could be a doubt for City's clash with AFC Bournemouth next Saturday.
