Argentina are hopeful Sergio Aguero will not miss the rest of the World Cup after the Manchester City striker was ruled out of their last 16 match against Switzerland through injury.
Aguero was subsituted after 37 minutes during Wednesday's 3-2 triumph over Nigeria.
Tests done on Thursday revealed a muscle injury to the 26-year-old's left leg.
"It's a first-degree muscle strain in his femoral biceps," Argentina team doctor Daniel Martinez said in Thursday's press conference.
"It's a degree lower within the muscular injuries. He will try to recover as soon as possible."
Martinez did not offer an opinion on whether Aguero would return and play in the quarter-final, if Argentina make it to the last eight.
"We have several (treatment) alternatives that we will evaluate regarding how it develops," he said. "We have all the available resources in order to get Sergio fit as soon as possible.
"The recovery already started on Wednesday. From Switzerland onwards, it will depend on whether Argentina remains in the competition and on his day-to-day recovery in order to see him back on the pitch."
Aguero's absence is a major blow to the South Americans' campaign to capture a third World Cup, this time on the soil of their great rivals Brazil.