Kovac - who only took over in mid-October - guided Croatia to the finals courtesy of a play-off victory over Iceland and their reward is the opening game of the tournament against Luiz Felipe Scolari's side.
The 42-year-old knows Mexico and Cameroon will also provide serious competition in Group A, but has hope of causing an upset against Brazil after previously meeting them in 2006.
"It is very special," said Kovac. "Brazil in the first game with the whole world watching, it will be something.
"We will try to make it difficult for them but it won't be easy.
"Look at 2006 though, we gave them a very difficult game (when losing 1-0). Dida made some good saves and Kaka scored a very late goal.
"I think Brazil is the obvious favourite but second place is wide open. Mexico may have struggled recently but they are always strong at the World Cup. It is really tight for second place."
After facing Brazil in Sao Paulo, Croatia will face Cameroon in Manaus and Mexico in Recife.
