Portuguese great Luis Figo has become the latest shock candidate for the role of Fifa president.
The ex-Sporting Lisbon, Barcelona, Real Madrid and Inter Milan forward, 42, wants to replace Sepp Blatter as boss of world football's governing body.
Royal Dutch Football Association (KNVB) president Michael van Praag also said on Wednesday he will be a candidate.
Blatter, 78, has been Fifa boss since 1998 and said in June 2014 that he intended to run for a fifth term.
Retired France international player David Ginola and fellow Frenchman Jerome Champagne, a former Fifa executive and ex-diplomat, have already announced their intention to stand against him, along with Prince Ali of Jordan who is backed by the Football Association.
Van Praag, meanwhile, is backed by the Scottish Football Association.
Figo is standing after Blatter was criticised for Fifa's handling of Michael Garcia's report into alleged corruption during the bidding process for the 2018 and 2022 World Cups.
"Football has given me so much during my life and I want to give something back to the game," the ex-Portugal international, who won 127 caps, said in a CNN interview.
"I look at the reputation of Fifa right now and I don't like it. Football deserves better. In recent weeks, months, and even years, I have seen the image of Fifa deteriorate.
"As I speak to many people in football - to players, managers and association presidents - so many of those people have told me that something has to be done."
Figo won the Ballon d'Or in 2000 and was Fifa world player of the year in 2001.
In 2000, he made a controversial move from Barcelona to bitter La Liga rivals Real Madrid for a then world record fee of £37m, and won the Champions League with Real in 2002.
Chelsea boss Jose Mourinho has offered his support to his fellow countryman's presidency bid.
He said: "Luis Figo's candidacy is a great step forward for football. His career over many years grants a better future for Fifa.
"I believe in his character and determination, as well as his passion for the game. He will be a president focused on football and its general improvement, acting closely with all federations."
|Fifa presidency campaign latest|
KNVB chief Van Praag says he wants to clean up Fifa's sullied image and expand the World Cup if he succeeds Blatter as president.
The Dutchman, 67, said that under Blatter's stewdardship, Fifa "is doing badly and has lost all credibility".
He added: "Fifa is constantly under suspicion. Of conflicts of interest, of nepotism, of corruption."
Van Praag said he submitted his candidacy to Fifa this week with backing from the necessary five federations - Belgium, Sweden, Scotland, Romania and the Faroe Islands - as well as the Netherlands.
Scottish Football Association president Campbell Ogilvie said: "We believe Michael has the experience, integrity and gravitas required to expedite the modernisation of world football's governing body.
"Having known him for more than 20 years, I believe he is the right candidate at the right time to restore harmony to the game."
Harold Mayne-Nicholls, the former head of Fifa's technical committee had been expected to announce his candidacy but the Chilean said on Wednesday that he will now not add his name to the ballot because he would not expect to beat Figo.
All potential candidates have to register their interest in standing before Thursday's deadline.
According to Fifa electoral committee member Dominico Scala, all confirmed challengers must pass an anti-corruption test.