I have checked Transfermarkt for further information about Neymar's current condition. It says that his return date is still unknown. Even though people are staying positive about his return soon I'm not that much sure for now. Missing the rest of the group matches will be bad for him of course. But hopefully he can catch up with the matches in the later stages.
As for the team they can find a solution to this actually. Because Brazil's most effective line is attacking obviously. There are so many talented wingers in the squad already. For example, Antony can fill his place as a player who can play on both wings.
Now most Brazilian fans make Neymar's injury a joke, some supporters from their country are very happy because Neymar is injured and cannot continue the match, because they think Neymar dives too much, even worse Brazilian fans cheer when Neymar's leg is injured, very much different from the Portuguese star and the Argentinian star,
They consider Ronaldo to be a king and consider Messi to be a god and consider Mane to be their savior, according to media reports that Neymar will retire early from the Brazilian national team.