Manchester City players Gabriel Jesus and Kyle Walker have tested positive for the coronavirus.
Jesus has seen limited minutes for Manchester City because of a thigh injury picked up in September.
The 23-year-old Jesus will miss Manchester City's upcoming three matches before the international break, in which Brazil is supposed to lock horns with Bolivia and Peru in the World Cup qualifiers.
Dressed in the national shirt, draped in Brazilian flags and wearing Gabriel Jesus masks, the residents of the tough Jardim Peri favela crammed into Bar da Gisele for the game against Costa Rica.
The world's most expensive player appears to have recovered fully from the fractured foot that required an operation in March, with the only slight concern being his possible lack of match fitness.
It will be the first time Brazil brings a prominent attacking foursome like the one that attracted all the headlines 12 years ago with Ronaldinho, Kaka, Ronaldo and Adriano.
The respected pollsters reported that this was the most tepid build-up to a cup since the question was first posed in 1994.
City picked up their first silverware of the Pep Guardiola era by sweeping aside Arsenal 3-0 at Wembley on Sunday.
Brazil international Jesus has not featured for the Premier League leaders since he suffered a knee ligament injury against Crystal Palace on December 31.
Prior to the game Guardiola had lavished praise on Napoli, who are top of Serie A with eight wins from eight games.
Manchester City conceded two penalties as they edged Napoli 2-1 to tighten their grip on Champions League Group F.
Sadio Mane was shown a straight red card for a challenge on goalkeeper Ederson, turning the tide completely against the Reds.