Cristiano Ronaldo trained with the Portugal squad after his World Cup participation was cast in doubt by a nagging injury problem.
The Real Madrid star has suffered from knee and thigh injuries since the end of last season.
Ronaldo, 29, had his left knee taped up as he took part in light drills on Friday.
The reigning World Player of the Year limped out of training on Wednesday with an ice pack strapped to his knee.
Portugal lost their opening match 4-0 to Germany and will face the USA in Manaus on Sunday.