United States forward Jozy Altidore returned to training on Sunday as he looks to regain fitness ahead of the World Cup.
Altidore, a first-choice striker in coach Bob Bradley's squad, sustained an ankle injury in training on Wednesday and was ruled out of Friday's 3-1 friendly win over Australia.
The 20-year-old Villarreal player, whose ankle did not appear to be strapped up in training, participated in a five-a-side practice game before doing some extra running with the coaching staff after the session.
Altidore, who was loaned out at Hull City last season, could miss his country's opening match against England in South Africa on Saturday if he fails to recover in time.
Edson Buddle, who scored two goals against Australia, is likely to start against the Three Lions should Altidore not be ready.
The U.S.A will also take on Slovenia and Algeria in Group C of the tournament.