Luiz Felipe Scolari's men, who started the tournament as clear favourites, failed to convince as they could only draw with the Mexicans in Fortaleza.
Sky Bet's Marcus Berry said: "With Brazil failing to impress we have put the outright price out slightly from 3/1 to 100/30.
"They are still 1/100 to qualify so a draw has not done them too much harm so despite a poor performance we are wary of making a drastic change at this time."
Argentina are just behind in the outright market at 7/2 with Germany the only other team not available at a double-figure price. They are 9/2 shots following Monday's 4-0 demolition of Portugal.
Earlier in the day, Belgium edged to a 2-1 victory over Algeria but the unconvincing nature of the win saw Sky Bet leave the much-touted dark horses at 22/1 for the trophy.