Argentina coach Lionel Scaloni defended Lionel Messi, saying the star was still key to his team despite a quieter Copa America campaign.

Messi has scored just once, from the penalty spot against Paraguay, in four games at the tournament, where Argentina reached the semi-finals courtesy of a 2-0 win over Venezuela on Friday.

Amid criticism of the Barcelona star, Scaloni defended Messi, saying there were no doubts over the 32-year-old.

"I think, along with many other people, that he [Messi] is an essential addition on the pitch," he told a news conference.

"If you were here to see how much he contributes in the dressing room, how much he contributes on the pitch for his team-mates, maybe you would think differently.

"I can assure you he is a big part of the team, we have no doubts about that."

Scaloni added: "Messi is Messi. He's the best, above everyone else."

Argentina's win sent them through to a blockbuster semi-final against Brazil in Belo Horizonte on Tuesday.

Scaloni is excited by the meeting between the rivals, with hosts Brazil having edged past Paraguay on penalties.

"This match will be something beautiful to experience for all of you, for all football fans out there," he said.

"For us on the bench, it will be harder. But it will be a beautiful game, very nice, and we will try to complicate things for them and try to win it."