Vinicius Junior acknowledged that he and his team-mates must improve following their goalless draw with Costa Rica in their opening game of the Copa America. 

The nine-time champions were frustrated by their opponents at the SoFi Stadium, with Los Ticos becoming only the third CONCACAF side to keep a clean sheet against the Selecao Canarinho at the tournament after Mexico (2001 and 2007) and Honduras (2001).

Brazil registered 19 attempts at Patrick Sequeira's goal, but only three were on target, with Rodrygo (6) and Lucas Paqueta (5) having the majority of those chances. 

Vinicius failed to make an impact on proceedings in Los Angeles and was replaced by future Real Madrid team-mate Endrick for the final 20 minutes. 

The 23-year-old has now been substituted in Brazil's last six competitive matches and knows Dorival Junior's side must improve to achieve success at the tournament. 

"We know we can improve, we have to improve," Vinícius said. "I also know what I can improve, evolve and do for our team."

Vinicius, who scored 24 goals in 39 appearances for Los Blancos this season, arrived at the tournament with the weight of a nation on his shoulders with all-time leading scorer Neymar, out of the Copa America due to injury. 

The Real Madrid winger has registered just one assist in his last five appearances for his nation, but has called for patience from the Brazil fans. 

"New coach, new players, everything takes time," Vinícius said. "Our fans want everything immediately done, but we're going little by little. In the next game, I'm sure we'll play much better because we now already understand what the competition will be like, what the pitch, what the referees will be like.

"Every time I enter the field for the national team, I have three or four players marking me."

Brazil face Paraguay in Las Vegas on Saturday before concluding their Group D campaign against Colombia, who beat the Albirroja on Matchday 1.