"My dream isn't over. It was interrupted by a play but it continues," Neymar, who has been ruled out of the rest of the tournament with a fractured vertebra, said in a video released by the Brazilian Federation.
"I'm certain that my team mates will do everything possible so that my dream, which is to be a champion, comes true.
"My dream was also to play in a World Cup final but this time it didn't work out," the 22-year-old said, his voice cracking with emotion.
"But God willing, they're going to win this, they're going to be champions, and I'm going to be by their side, with them. And all us Brazilians are going to be celebrating."
Neymar, who scored four goals in the tournament, suffered the back injury during Friday's 2-1 quarter-final win over Colombia. Brazil will play Germany in the semi-finals on Tuesday in Belo Horizonte.
Globo TV, the country's most popular network, broadcast Neymar's message during a live variety show on Saturday. The crowd gave it a standing ovation and many were in tears.
Neymar was strapped to a stretcher on Saturday when he was loaded into a helicopter to fly from the team's training base to his home on the coast near Sao Paulo.
But he was sitting and appeared to be comfortable in the video, and Brazil's team doctor said Neymar might be able to attend Tuesday's match as a fan.
"It will all depend on his pain," Jose Luiz Runco told reporters.
"If he's without pain and comfortable, nothing is forbidden and nothing will compromise his recovery. He just has to be seated, and comfortable with airplane travel."
Runco said recovery should be complete within 45 days, and that Neymar would be able to sit and walk in the meantime.
Several dozen fans gathered outside the forward's home in Guaruja to welcome him back, many carrying signs that said "Strength, Neymar."
His father came outside and applauded, giving the crowd a thumbs-up.
- Sports & Recreation