Altidore scored twice in 30 appearances for Hull last season
American fears over Jozy Altidore's fitness appear to have eased after the Villarreal man returned to training.
The 20-year-old, on loan at Hull last season, missed Friday's 3-1 warm-up win over Australia due to an ankle injury sustained in training on Wednesday.
But after taking part in a five-a-side game on Sunday the first-choice striker will be expected to face England in the United States' opener on 12 June.
However, neither Altidore nor coach Bob Bradley commented after the session.
Los Angeles Galaxy's Edson Buddle, who scored twice against Australia, is the favourite to deputise up front should Altidore not be ready for the Group C clash against Fabio Capello's side in Rustenburg.