When a player is injured, usually in the national team announcement, the injured player is excluded and then the team is announced. Injury problem is usually a big problem for every team and every player and no matter how big a star a player is if he is not fit for full game then he is not allowed to play as well as he is not selected in the national team announcement. But now Neymar is performing regularly for a prestigious club in Brazil and his game looks like he is back in good form. If Neymar can perform like this up front, I believe he will definitely be included in the Brazil national team again. Maybe Neymar is still playing football just to play one more World Cup for Brazil. The World Cup isn't long until the start, but Neymar will want to stay fit before the World Cup squad is announced.
After the reign of Neymar in Brazil National team, Brazil has never been the same again. They look like an average country in football currently, because the current players are unable to maintain the standard of the country when it comes to football. It will be lovely to see Neymar back to the National team in good form if possible.
The collapse of the Brazilian national football team does not depend on Neymar being in charge of the squad, but in my observation there are many factors that cause the Brazilian national team to become as usual. Brazil, which was supposed to be the strongest team in the world cup, is now just a memory, since 10 years ago, twice in the world cup competition, Brazil is no longer a squad that is feared by opponents.
The reason why all this happened, Brazil does not have a successor like Roberto Carlos, Ronaldinho and also several other senior players, so I don't think the Brazilian national team will return with the best performance if just rely on Neymar.