Carlo Ancelotti hasn't officially taken up his position as Brazil's coach yet. He will do so on July 1. But he is already facing his first major problem.
The "canarinha" attack is full of stars... and egos. It will be a pressure cooker for the new coach.
Neymar and Raphinha make their move

Neymar and Raphinha have been the first to make their move, and both demand clarity: they want to be starters, not substitutes for anyone. That directly compromises Vinícius Junior, whose role could change drastically.
The Italian coach's idea is to build a forward line with balance, and that means there's only room for one pure "9" and two wingers. Neymar doesn't accept playing as an attacking midfielder and Raphinha arrives in his best form at Barça, with numbers that support his starting position. In light of this, Vinícius's position is shaky, just when it seemed he had everything secured.
In Brazil, they haven't overlooked Vinícius's disappointing season at Real Madrid. Ancelotti, who already feels betrayed by the winger's attitude in recent months, doesn't plan to gift him the position.
The relationship between Ancelotti and Vinícius has cooled

Between absences in major matches, his poor performance in the Clásico, and his growing tension with teammates, Vinícius's relationship with Ancelotti has notably cooled.
Ancelotti knows he can't bench Neymar for political reasons, nor Raphinha for sporting reasons. The big casualty could be Vinícius, who might go from being the great hope to fighting for minutes. A new situation for him, but one that Ancelotti won't hesitate to apply.
The Italian coach won't gift him anything. He is very upset with his attitude during the substitution in the Clásico, even implying that he decided the substitution himself.
Everything indicates that Brazil's locker room could be a ticking time bomb, and the coach is already starting to feel it even before debuting. If he has protected Vinícius at Madrid, in Brazil he will have to make unpopular decisions. Vinícius knows it.