Sepp Blatter could remain as Fifa president unless a "convincing candidate" comes forward to replace him, according to one of his advisors.
Klaus Stöhlker, who was one of Blatter's closest advisors during his last presidential election campaign, said the Swiss national could remain in charge of football's world governing body despite announcing his intention to step down in the wake of the corruption allegations.
Swiss media have already speculated that Blatter could stay in as Fifa president after being urged to hold onto his post by African and Asian football associations.
Stöhlker has now said Blatter will seriously consider a U-turn on his resignation if there is not a suitable replacement for the 79-year-old.
He told Sky News: "At the moment there is not a convincing candidate to replace Mr Blatter with the same level of qualifications, of languages, of contacts, and knowledge of football.
"As long as there is not such a candidate it remains open for Sepp Blatter to run again. There are some people that are asking him not to stand for the next election, there are some people that are asking him not to resign.
"He is the man who made FIFA with 40 years of hard work. He can tell if there is a really high-grade challenger who has got the qualities, who can balance between the demands of the Confederations, then I think he won't have a problem to resign. But at the moment there is not a candidate."
Uefa president Michel Platini and Prince Ali of Jordan - who Blatter beat in the last presidential election days before he announced will retire - are among the names rumoured to be in the running to stand in the next election, scheduled to take place between December and March 2016.