Luis Suarez reportedly limped out of a training session just three days before Uruguay's meeting with France in the World Cup quarter-finals.
La Celeste are already sweating on the fitness of Edinson Cavani, who has been unable to take part in any sessions since injuring his hamstring late on in the 2-1 win over Portugal last weekend.
According to Spanish publication Marca, Uruguay face a double blow as Suarez injured his right leg during training at the team's base in Nizhny Novgorod on Tuesday.
The Barcelona star later returned to the field, but boss Oscar Tabarez is said to be concerned ahead of Friday's showdown with France.
Speaking to reporters earlier on Tuesday, Suarez insisted that Uruguay can cope without Cavani if his strike partner fails to recover from injury.
