The Swiss believes that such a move would be inconsistent, as it has not been applied for the qualifiers so far.
"All around the world, the qualifying system is done with the conservative system of one referee, two assistant referees and the fourth official," Blatter is quoted as saying by Reuters.
"I'm not going to say what is the final decision before the World Cup, but if you have the system which has run for the qualification, then you should have the same system in the final."
Blatter added that extra officials in a match are too expensive for most domestic leagues.
"There are not so many associations in the world of football that can afford to have so many referees, even in professional leagues," he said.
"The referees [behind the goals] must have the same quality as the referee in the middle, that is the first principle.
"Let us wait and see how many of the national associations will use this system of additional referees and how it will work in the different leagues."
UEFA president Michel Platini has backed using more referees behind the goals instead of video technology in football.