The midfielder and full-back, both 28, had never previously been called up by Scolari, but have forced their way in ahead of this year's showpiece thanks to their form for clubs Manchester City and Bayern Munich.
Fernandinho and Rafinha - whose last caps came in 2012 and 2008 respectively - join first-team regulars such as Thiago Silva, Dani Alves, Oscar, Hulk and Neymar in a 16-man selection of foreign-based players for the friendly against South Africa on March 5.
Scolari will add home-based players five days before the fixture in Johannesburg, in order to give Fred, who led the line during Brazil's triumphant FIFA Confederations Cup campaign in 2013, the chance to recover from a thigh injury.
Dante, Ramires, Willian and Bernard have also retained their places in the squad, but Marquinhos, Maicon, Maxwell, Hernanes and Lucas Moura have been overlooked.
"Fernandinho's been playing really well for Manchester (City), he's been attracting attention ... so here's his opportunity," Scolari explained.
"Rafinha's also been playing really well for Bayern. He's had experience of playing for the national team at other levels."
Goalkeeper Julio Cesar, who recently joined Toronto on loan from QPR, kept his place despite seeing very little action since his parent club's relegation from the Premier League last term.
"We wanted him to play regularly," Scolari said of Cesar.
"Obviously we hope that (he) is playing week in, week out, but he's the type of player who could go into a World Cup having seen little action and still do his job. I need players I can trust 100 per cent."
Squad in full:
Goalkeeper: Julio Cesar (Toronto)
Defenders: Dani Alves (Barcelona), Dante (Bayern Munich), David Luiz (Chelsea), Marcelo (Real Madrid), Rafinha (Bayern Munich), Thiago Silva (Paris Saint-Germain)
Midfielders: Fernandinho (Manchester City), Luiz Gustavo (Wolfsburg), Oscar (Chelsea), Paulinho (Tottenham), Ramires (Chelsea), Willian (Chelsea)
Forwards: Bernard (Shakhtar Donetsk), Hulk (Zenit), Neymar (Barcelona)
