"I will be fine in a week," a straight-faced Nani told the SIC TV station at Lisbon airport when asked how long he would take to recover from the injury that forced him to fly home early.
Portuguese media outlets have been puzzled by the in-form Manchester United player's injury, particularly the timing of the events.
The winger damaged his shoulder while performing a bicycle kick during a training session on June 3, but flew with the rest of the squad to South Africa two days later.
He trained for two days before being ruled out with Portugal coach Carlos Queiroz saying the player was in too much pain to continue.
The Portuguese Football Federation has maintained that the player was injured, with its vice-president Amandio de Carvalho dismissing reporters' questions of a disciplinary problem with the technical staff.
"There is no intention of hiding anything, there was just the hope that he could recover," de Carvalho told reporters on Thursday.
"I thought this was going to be my World Cup, but I injured myself before that start and now I only think of getting well," Nani said before sparking controversy by adding that the recovery would take a week.
Portugal play their first game against the Ivory Coast on Tuesday, followed by matches with North Korea and Brazil.
