Ex-Portugal midfielder Figo, 42, pulled out on the same day as Van Praag, 67, to leave Prince Ali Bin Al-Hussein of Jordan as Blatter's only rival.
Blatter is favourite to win a fifth term as president and Figo said: "This process is anything but an election.
"This process is a plebiscite for the delivery of absolute power to one man - something I refuse to go along with."
Each of Fifa's 209 member associations have a vote in the election and Van Praag, who is president of the Dutch football federation, says he will now support Prince Ali.
The English Football Association also intend to support Prince Ali, while the Scottish FA had previously said they would back Van Praag.
The Dutchman held a joint news conference with Prince Ali in Amsterdam on Thursday, urging his supporters to get behind the Jordanian to unseat Blatter.
"Prince Ali Bin Al-Hussein convincingly demonstrated that at this moment in time he is the candidate who has the biggest chance to challenge Sepp Blatter," Van Praag said.
"It is impossible that Fifa moves on with its current presidency," he added.
Figo also highlighted the need for change in his withdrawal statement.
"I travelled and met extraordinary people who, though they recognized the value of much that had been done, also concurred with the need for change, one that cleans up Fifa's reputation as an obscure organization that is so often viewed as a place of corruption," he said.
"I have seen with my own eyes federation presidents who, after one day comparing Fifa leaders to the devil, then go on stage and compare those same people with Jesus Christ. Nobody told me about this. I saw it with my own eyes."
He also questioned an election process in which a main candidate - Blatter - had not produced a manifesto "so that federation presidents know what they're voting for".
Figo added: "There has not been a single public debate about each candidate's proposals."
The latest withdrawal comes after another presidential candidate, Frenchman Jerome Champagne, a former Fifa deputy general secretary, pulled out in February.
Former Tottenham and Newcastle midfielder David Ginola, backed by a betting company, originally announced his intention to stand against Blatter in January, but withdrew two weeks later.
The vote will be held in Zurich at Fifa's annual congress and requires the winning candidate to secure a two-thirds majority in the first round of voting.
If subsequent rounds are required then a simple majority is all that is required for victory.

Emily Titterington had not been to the toilet for three months when she suffered a cardiac arrest at home.
An inquest heard the condition was so bad that some body parts had been displaced, including her diaphragm.
The Coroner for Cornwall concluded the cause of death was "natural causes contributed by psycho-social factors".
Summing up, Dr Emma Carlyon said it could have been prevented.
"Something went wrong with the patient-parent-professional triangle which meant she did not get the care she needed," she said.
Paramedics described their "shock" at Emily's "grossly extended abdomen" when she collapsed at St Austell in February 2013 and said she was "vomiting faeces".
The inquest was told that Emily, who was home-educated, had a history of constipation that could be linked to her anxiety and mild autism.
Her sister Hannah Herbert raised concerns about the impact "parental anxieties" had on her, and said she had warned social services "something terrible might happen" the year before.
Her brother-in-law Brian Herbert told the inquest Emily's decision not to be examined or go to hospital would have been influenced by the fact her parents "could not cope" with that.
However Emily's GP, Dr Alistair James, said her mother Geraldine Titterington had tried to persuade her to be examined and he found no evidence of safeguarding issues.
Consultant paediatrician Dr Paul Davis said "self-neglect" played a part in her death but she should have been persuaded to go to hospital.
A serious case review by Cornwall Council's Safeguarding Children Board has made several recommendations including that agencies share concerns raised by a family member.
Dr Carlyon said she was satisfied "most of the recommendations have been actioned and embedded".
Luis Figo has joined Michael van Praag in withdrawing from the Fifa presidential election on 29 May.
[NEXT_CONCEPT]
A 16-year-old died from chronic constipation because either she, or she and her parents, resisted the care she needed, a coroner has said.