Brazil face Paraguay in their Copa America Group D match in Las Vegas on Saturday morning (7am, Bangladesh Time) after a disappointing goalless draw against lowly Costa Rica in their opener left the five-times World Cup winners questioning how to sharpen their cutting edge.

A wasteful Brazil side dominated possession but were clueless on how to beat an ultra-defensive Costa Rica playing with a back five. They roamed around their opponent's box but were toothless, with just three of their 19 shots on target.

Paraguay, who lost 2-1 to Colombia in their first game, are expected to use a similar defensive game plan to Costa Rica.

That will pose another challenge for Brazil's 62-year-old manager Dorival Jr who will have to find answers on how his side can break deadlocks and be more precise in front of goal.

Attacking midfielder Lucas Paqueta, one of Brazil's most active players against Costa Rica with five shots that missed the target and one that hit the post, believes their problem is more mental than tactical. He thinks Brazil need patience.

"We had lots and lots of chances, I had three in particular that I should have done better (with), we just needed to finish with a bit more composure," Paqueta told a press conference on Wednesday.

"It's clear that finishing from outside the area against teams who close down and defend deep is something that we can improve, but we are still very confident that we will."

NO EXCUSES

Missing talisman Neymar, who is still recovering from a serious knee injury, there was a general impression that Dorival was ready to hand rising star Vinicius Jr a key role after the winger's brilliant season with Real Madrid.

But the 23-year-old was a shadow of the electric winger who helped Real win a Champions League/LaLiga double and he was taken off after 70 minutes, leaving fans and pundits scratching their heads as Brazil squandered one chance after another.

The frustration was such that even Brazil captain Danilo, known as a cool-headed and composed personality on and off the pitch, lost his temper and had to be restrained by team mates for confronting a fan in the stands after full time.

"We can't keep making excuses about the pitch or their low defensive line. It was a draw that tasted like defeat for us, so we have to improve, no excuses," forward Rodrygo told reporters.

There is no indication Dorival will make any changes against Paraguay despite the growing pressure from fans and media who are eager to see teenage sensation Endrick starting alongside his future Real Madrid team mates Vinicius and Rodrygo up front.

The 17-year-old striker Endrick was Brazil's hero in Dorival's first two games in charge earlier this year.

He became the youngest player to score at Wembley in a 1-0 win over England and a few days later got the equaliser that helped Brazil fight back to draw 3-3 with Spain, leaving Real fans salivating as he will soon join the European champions.

Dorival does not want to rush the teenager into a starting role but after a run of five straight games without a win in competitive matches, Brazil's worst record in 23 years, the manager could soon be forced to listen to the crowd.