The Real Madrid forward spoke to the Brazilian media after scoring in Brazil's 4-2 friendly victory over Australia.
Vinicius played a decisive role in the win, winning and converting a penalty before scoring Brazil's fourth goal of the match. Endrick also found the net as Carlo Ancelotti's side secured victory.
The performance offered Vinicius some encouragement after a difficult opening period with both Real Madrid and Brazil.
“My team-mates know that I need some confidence at the moment,” Vinicius said.
The forward also pointed to Brazil's World Cup exit as a factor in his difficult period.
“Losing a World Cup is tough and difficult to accept, and the return is never easy,” he said.
Brazil were eliminated by Norway in the quarter-finals of the previous World Cup, a result that Vinicius said had continued to weigh on him.
His goal against Australia therefore represented a positive moment after a period in which his form had been questioned.
Ancelotti, who is now coaching Brazil after his departure from Real Madrid, also addressed Vinicius' situation after the match.
The Italian acknowledged that Vinicius is not currently at his best but rejected the idea that his importance to Brazil had diminished.
“He is a fundamental player for the national team, for Brazil, for my footballing history and for the future,” Ancelotti said.
“Is he at his best at the moment? No, but it is the beginning of the season. Even when he is not at his best, he can make the difference, as he did today.”
Ancelotti also called for patience with the Real Madrid forward.
“With him, you have to be patient because he deserves that patience,” the Brazil coach said.
Vinicius' performance against Australia came during a period in which his form for Real Madrid had also attracted scrutiny. His contribution for Brazil, however, gave him an opportunity to regain some confidence ahead of the next stage of the season.
The forward's comments suggest that the psychological impact of Brazil's World Cup disappointment has remained part of his experience since the tournament ended.
For Ancelotti, meanwhile, Vinicius' importance remains clear despite the player's current struggles for consistency.