Rio de Janeiro: Brazil renewed their criticism of the World Cup ball on Thursday, coach Dunga saying players from other countries were also unhappy with it.
Dunga was also angry with FIFA general secretary Jerome Valcke, who implied during a news conference this week that, in criticising the ball, Brazil were looking for excuses in case they failed to win the tournament.
"All he (Valcke) has to do is play," Dunga told reporters. "If he plays he will have a different opinion."
"The guy has never gone on the pitch, never kicked a ball, the only thing he knows how to do is talk."
"Let`s put him on the field to play, to come and train here with us, with this ball, and afterwards we can talk."
Brazil striker Luis Fabiano has described the ball as weird while goalkeeper Julio Cesar called it horrible and said it resembled a cheap ball bought in a supermarket.
Dunga said his squad were not alone.
"It`s not just the Brazilian players who are complaining, it`s players from a number of countries," he said.
"But that`s the ball we have to play with so there`s no way around it, we have to adapt."
Brazil, who beat Zimbabwe 3-0 in a friendly on Tuesday, face North Korea, Ivory Coast and Portugal in their first-round group.
The coach also took aim at the Brazilian media.
"We`ve got 300 journalists here who don`t want Brazil to win," he said. "They want to be able to say that I was lucky when we won the Copa America and the Confederations Cup."
"But it doesn`t just happen to me, it happens to every coach of Brazil."
I`ve got my strength back, which is nice. Now the next goal is to get my explosiveness and my fast twitch going, and that`s the next phase of my training.