The host nation play just two warm-up fixtures in the build-up to the tournament, beginning with Panama's visit to Goiana.
However, coach Scolari is unlikely to offer too many hints over his preferred line up ahead of the curtain-raiser against Croatia on June 12.
"For this first match we will follow what the medical department tells us," Scolari is quoted as telling Brazilian television. ''The group will be evaluated again over the weekend and then we will know who will be fit.
"We don't want to risk anything before the World Cup."
Brazil's preparations conclude with a match against Serbia on Friday, when Scolari hopes to have a full 23-man contingent at his disposal.
"For the second match we will likely have all 23 players available and we will be able to set up the team the way we want,'' he added.
But Scolari will have to contend with a squad of players who are desperate to book a place in the Brazilian starting XI, including David Luiz, who could be one of those to miss out on Tuesday after reportedly spending time training separately from the main group.
''Everyone is fine, but there are some minor adjustments to be made in the preparations,'' the Chelsea defender said. ''I want to play. I hope Scolari will let me.''
To the untrained eye, Panama might appear strangely weak opposition for the tournament favourites to come up against as they prepare to lift the trophy for the first time since 2002.
Bordered by World Cup entrants Costa Rica and Colombia, Panama have never qualified for the global showpiece themselves.
However, the small Central American nation have steadily climbed from a FIFA rankings low of 150 in 1995 to a high of 29 earlier this year, and currently sit 35th - a place below neighbours Costa Rica.
In fact, a winning margin of two or more over United States in the final round of CONCACAF qualifying would have been enough to see Panama deny Mexico their place in a World Cup play-off against New Zealand, but a 3-2 home defeat saw them fall three points short.
Instead, they visit Brazil for a pre-tournament friendly - scant consolation for a team who came so close to a finals berth.
