The Brazilians are playing their first home match since suffering a shock 2-1 defeat to Mexico in the gold medal match at London 2012 last month - a result that drew huge criticism from back home.
Supporters also appear to be indifferent to the clash with the South Africans, despite it also being Brazil's first game at home in 15 months, with only half the tickets sold to date.
However, Neymar has urged the fans to come and back the team at Morumbi stadium, stressing how important they are for the game.
"Football is not football without the fans. They're the heart of the game. We really hope that the Brazilian people come to see and cheer us," said the Santos forward.
Brazil coach Mano Menezes is waiting on the fitness of a couple of players ahead of Friday's match in Sao Paulo.
Barcelona full-back Dani Alves was unable to train due to a pain in his right leg, and his place could go to club-mate Adriano, while midfielder Sandro is also a doubt.
Despite those concerns, Menezes is still set to name a strong side which could include Chelsea trio David Luiz, Oscar and Ramires and attacking trident Lucas, Neymar and Leandro Damiao.
For South Africa, the friendly will see new coach Gordon Igesund take charge of his first match following his appointment in June.
It might also see former Porto and Blackburn striker Benni McCarthy earn his 80th cap, leaving him clear in second place in the country's all-time list behind Aaron Mokoena.
The Bafana-Bafana have arrived in Sao Paulo with several selection dilemmas, though, as Steven Pienaar, Anele Ngcongca, Siyabonga Nomvete and Edward Manqele have all been ruled out through injuries.