Real Madrid team-mates Kaka and Marcelo will miss Brazil's friendlies against Gabon on Thursday 10 November and Egypt four days later.
"The players are prevented from playing due to muscular injuries, as confirmed by scans sent by Real Madrid to the Brazilian national team's medical department," the Brazilian football association (CBF) said.
Kaka was set to make his first international appearance since their World Cup quarter-final exit in South Africa last year.
The former World Footballer of the Year has regained his place in the Real squad recently and put in some impressive performances, after a string of injury problems blighted his 2010-11 season.
Real's coach Jose Mourinho had already said that Kaka would have to wait a little longer before returning for Brazil as he was nursing a calf injury.
"He wouldn't have time to recover. It's an injury that has nothing to do with the serious problems of the past," Mourinho said.
"It's a small injury typical of those that happen every season and he's going to stay here 15 days to recover."
The CBF also added that Bayern Munich midfielder Luiz Gustavo would miss Thursday's match in Gabon because he had not obtained proof of a vaccination needed to enter the African country.
But it added he would be available to play against Egypt in Qatar on 14 November.
Brazil, the 2014 World Cup hosts, meet Gabon in Libreville on Thursday to mark the opening of the new stadium built for January's Africa Cup of Nations finals.