By Ben Hayward in Belo Horizonte
Argentina striker Sergio Aguero has been ruled out of his side's second-round clash against Switzerland next week and could miss the rest of the competition, Goal understands.
Aguero recovered from a muscle problem in time to start the World Cup, but has looked short of full fitness in Brazil and picked up a similar injury in the first half of his side's 3-2 win over Nigeria on Wednesday.
The Manchester City striker underwent treatment to begin his recovery that very night after it was confirmed he suffered a grade-one muscle tear in his left thigh, Argentina team doctor Daniel Martinez revealed on Thursday, but the 26-year-old already been ruled out of the game against Switzerland.
"We have some alternatives [in terms of treatment] and we'll evaluate them depending on how his recovering is going," Martinez told reporters after Argentina's training session in Belo Horizonte.
"We have all the necessary resources to get Sergio back as soon as possible, but we will assess him on a day-to-day basis after the Switzerland game."
If Argentina get past Switzerland, Alejandro Sabella's side will face either Belgium or USA in the quarter-finals on July 5, with a possible semi-final against Netherlands, Mexico, Costa Rica or Greece four days later, before the final in Rio de Janeiro on July 13.
Recovery time for Aguero's injury is usually between two to three weeks, making the 26-year-old a big doubt for the remainder of the competition.