Brazil, the only team to have played at all 18 World Cups and winners of a record five, begin with a tricky match away to Colombia in Bogota on October 14.
They host Ecuador in Rio de Janeiro three days later in their first home match for two years and their first at the famous Maracana since a 5-0 win over Bolivia in 2000.
Although Brazil have never failed to reach the finals, they have had some tricky moments in the past, especially in the qualifiers for 2002 when they lost six of their 18 matches.
"The qualifiers are much more difficult than the finals," said Dunga. "Everyone wants to beat Brazil, we're the only team that speaks Portuguese, there's the atmosphere, the away games.
"Against Brazil, the other teams play with more determination and they change their characteristics. We have to be ready for any surprise, any difficulty."
"In the finals, we play on neutral grounds and the opponents are more open."
But the coach said he was confident his squad was good enough to keep Brazil's proud record intact.
"This is a group with a strength to revert unfavourable situations, they react positively in difficult moments and they know what they want," he said.
"It's a competitive squad with great quality."
Dunga shrugged off criticism of his forwards, who between them have produced only one of the nine goals Brazil have scored in their last three games.
"There's a big pressure on the strikers to score goals but the team's goal average is good. We play a style where all the players score.
"It doesn't matter who scores, when you pass the halfway line you become a forward."
Despite last week criticising the pitch at the Maracana, he welcomed the return to the famous stadium.
"It's a stage where all the players are happy to perform. There's nothing better than playing at the Maracana," he said.