American forward Jozy Altidore, right, is day to day with a sprained ankle. ((Hunter Martin/Getty Images) )

U.S. forward Jozy Altidore has sprained an ankle during training.  

Altidore hurt his right ankle during a workout on a field with small goals Wednesday, U.S. Soccer Federation spokesman Neil Buethe said. Altidore was taken to a hospital for X-rays and was diagnosed with a mild sprain.  

"It's nothing more than that," Buethe said Thursday. "He'll undergo a fitness test tomorrow to determine whether he can play Saturday."  

The U.S. faces Australia on Saturday in Roodepoort in the final friendly for both teams ahead of the World Cup. The Americans open against England on June 12.