Sepp Blatter could be open to the possibility of standing for re-election as Fifa president, the BBC understands.
The 79-year-old said he was standing down as the head of world football's governing body less than two weeks ago, just four days into his fifth term.
A new president was expected to be elected, probably in mid-December.
But a source close to Blatter has told the BBC the Swiss could make an audacious bid to stay on if no suitable alternative candidate emerges.
"Everything is open," said the source.
Blatter will hold meetings over the coming days when he will gauge whether he still retains enough support to seek an astonishing sixth term as president.
Fifa has officially referred inquiries over Blatter's intentions to his resignation speech on 2 July, in which he promised to start work on new reforms and said "I shall not be a candidate" in the next election.
However, in 2011 Blatter also claimed his fourth term would be his last, only to renege on the pledge. It is now possible he could attempt a similar, but even more controversial U-turn.
Any attempt by Blatter to cling to power will be met with fierce opposition in the wake of the FBI-led corruption investigation that has plunged Fifa into turmoil and seen the arrest of several senior football officials.
Many critics have demanded that Blatter steps down immediately, rather than wait until an extraordinary meeting of the Fifa Congress in the winter.
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Many feared he would use his remaining months in charge to try to ensure the election of a favoured successor. Now it appears he may choose to sensationally stand himself.
Tellingly, the man entrusted to lead Fifa out of its latest crisis has appeared to warn Blatter not to rethink his resignation.
Domenico Scala, chairman of Fifa's audit and compliance committee, said it was "indispensable to follow with the initiated process of the president's change as has been announced".
The statement was in response to a report in Swiss newspaper Schweiz am Sonntag that Blatter had not ruled out remaining in office after receiving support from football officials in Africa and Asia.
But Scala, who has been given the task of overseeing the election of Blatter's successor, said: "For me, the reforms are the central topic."
His statement is the first sign of potential tension between the pair.
One of the reforms Scala has recommended, as well as greater financial transparency and a new governance structure, is three terms of a maximum 12 years in total for both the president and Fifa executive committee members.
Blatter has already served 17 years as the sport's most powerful figure.
Campaign group New Fifa Now has insisted an independent reform commission is the only means of ensuring meaningful changes to the way football is run.
Ever since he announced his resignation, those vying to replace Blatter have been considering when to make their move.
If he does stand again, he may look to present himself as the best means of avoiding one confederation - such as Uefa - gaining excessive power.