Brazil striker Ronaldo is optimistic he will face Venezuela in Saturday's World Cup qualifier while Juan has been preferred to Lucio in the centre of the defence.
Ronaldo arrived at the training camp of the world champions on Monday with problems in both thighs but he told reporters on Wednesday that the injuries appeared to be clearing up.
"I'm not feeling any pain and I don't think there will be any problem for me to play," said the Real Madrid striker, who missed Sunday's 1-0 defeat by Deportivo Coruna in the Spanish Primera Liga.
"I'm only going to play if I'm 100 percent fit," added Ronaldo, who again trained separately on Wednesday.
"I left Spain with a slight sprain, the time for recovery was one week and that time has passed."
FINAL DECISION
Coach Carlos Alberto Parreira said a final decision would be made on the striker after Thursday's practice match.
"The chance of him playing is good. I hope that he doesn't have any problem in training tomorrow (Thursday)," he said.
Parreira confirmed that Juan would keep his place alongside his Bayer Leverkusen team mate Roque Junior at the heart of the defence, even though Lucio, the regular first choice until earlier this year, had recovered from a knee injury.
The coach's decision was a reward for Juan, who an excellent Copa America followed by flawless performances in last month's World Cup qualifier against Bolivia and friendly against Germany.
Parreira said that playing for the same club was a big plus for the pair.
"I like Lucio a lot but Juan's been playing since May and has proved he's a good player," he said.
Brazil, who lead the 10-nation South American qualifying group with 16 points from eight games, face Venezuela away in the sweltering oil city of Maracaibo before taking on Colombia at home in Maceio four days later.