The FIFA president has voiced his discontent with the tournament's organization, while he is confident Brazilians "will not attack football directly."
Several venues - including the Sao Paulo Stadium where two workers died in November - were not completed in time to meet FIFA's deadlines and Blatter is not impressed with the nation's preparations ahead of this summer's showpiece.
"Brazil has now come to realize that they started too late," Blatter was quoted as saying by 24 heures. "They are the country who are the most delayed in terms of World Cup organization since I have been at FIFA, even though they had such a long time [seven years] to prepare."
Last year's Confederations Cup in Brazil was marred by civilian protests against the costs of the World Cup, yet Blatter thinks it's unlikely this summer's tournament will come under threat.
"I am an optimist, not a pessimist. Football will be protected. I believe that Brazilians will not attack football directly. This is the sport's home, it's a religion. But we know there will be new demonstrations, protests. Last year, they were born of social networks. There was no goal, but at the World Cup they will be more directed, more structured."
The World Cup is scheduled to kick off June 12, with the final taking place July 13.