In an interview with Swiss state broadcaster RTS shown on Friday, Blatter outlined what it would take to stand again in a May 2015 poll. He would be 79 then.
"I'm not announcing now that I'm going to be a candidate, but if the member associations asked me to be a candidate, I would not say no," said Blatter, adding that his health was good.
The 209 member countries have their best opportunity on June 10 in Sao Paulo at their annual congress ahead of the World Cup opening match.
Blatter could use the congress to pre-empt a widely predicted candidacy from UEFA President Michel Platini, who has refused to commit before the World Cup.
Four years ago, Blatter sought and received acclamation from FIFA's congress in Johannesburg to seek a fourth four-year term the following year.
Blatter has intimated regularly he will run again despite pledging in 2011 — at a UEFA congress chaired by Platini in Paris — that this term would be his last.
"If I am in health, and actually I am in good health, I don't see why now I should think to stop work," said Blatter, who was elected president in 1998. He is in his 39th year working for football's world governing body.
Blatter, an International Olympic Committee member, gave the interview on the sidelines of the IOC's annual meeting ahead of the Winter Games. He was scheduled to leave Sochi before the opening ceremony late Friday.
Blatter's promise in 2011 came during a bitter campaign against Mohamed bin Hammam of Qatar, who withdrew his candidacy days before polling when implicated in trying to bribe voters from the Caribbean.
Former Blatter aide Jerome Champagne declared last month his intention to seek the FIFA presidency, though the French former diplomat acknowledged he was unlikely to challenge his one-time boss directly.