The Gremio custodian, who was number one for Brazil at the last South American Under-20 Championship, was given the sudden call to replace Helton.

The Porto man picked up an injury to his left-thigh muscle prompting the national coach to summon for Cassio, a call Dunga hoped would help see more of the player predicted to be part of the national team at the 2008 Olympic Games in Beijing.

"It is not the best way for Cassio's chance to arrive after another injury," Dunga told the Brazil Football Confederation website, www.cbf.com.br.

"But his call-up is part of a plan made by the technical staff to watch some players who can be used in the Olympic team."

The 19-year-old Cassio, meanwhile, is delighted with the opportunity, saying: "I cannot believe this is happening to me.

"This dream will only come true when I meet the players and the coaching staff at the airport before the flight," he added.

Defenders Alex (PSV Eindhoven), Luisao (Benfica), Rafael Sobis (Real Betis), Naldo (Werder Bremen), Edu Dracena (Fenerbahce) and Ricardo Oliveira (AC Milan) have all withdrawn from the squad due to injury.

Brazil play Chile in Gothenburg, Sweden on Saturday, before meeting Ghana in Stockholm three days later.