Sergio Agüero picked up a hamstring injury and is now a serious doubt for Argentina's last sixteen game on Tuesday.
Agüero limped off injured in the 37th minute of the game against Nigeria and was replaced by Lavezzi. The Manchester City striker grabbed his upper left leg and left the pitch visibly in pain.
According to sources at the Argentine Football Association (AFA), the striker suffered a minor hamstring tear and is expected to miss the last sixteen game on 1st July.
Sabella admitted that he will start looking at alternatives. "We have strikers who play just like Agüero, and others with a different style, like Lavezzi, who came off the bench today and put in a great performance up front and also helped to plug gaps," said the Argentina boss.
Messi lamented Agüero's injury. "Hopefully it's nothing and he rejoins us quickly, he's a key player for us," he said.