Former Portugal forward Luis Figo pulled out of the FIFA presidential election race, hours after Dutchman Michael van Praag had also withdrawn.
Van Praag has switched his support to FIFA vice-president Prince Ali bin al-Hussein of Jordan who remains the only challenger to incumbent Sepp Blatter for the FIFA election..
Blatter is strongly favoured to extend his 17-year reign with a fifth term when the 209 national federations vote next week.
Blatter has pledges of support from most voters in five of FIFA's six continental confederations. Only UEFA is formally opposing Blatter and has supported all three opponents who were declared as candidates in January.
"My decision is made, I will not stand in what is being called an election for the FIFA presidency," Figo said on his Facebook page.
"After a personal reflection and sharing views with two other candidates in this process, I believe that what is going to happen on May 29 in Zurich is not a normal electoral act. And because it is not, don't count on me. There has not been a single public debate about each candidate's proposals.
"This electoral process is anything but an election.
"This (election) process is a plebiscite for the delivery of absolute power to one man - something I refuse to go along with."
It was long expected that at least one of Blatter's rivals would withdraw before election day to unify opposition.
Although Van Praag is a member of the UEFA executive committee, he had appeared to be the most independent of the three challengers.
He pledged to serve a single four-year term to modernise FIFA and improve transparency, and offered Blatter an advisory role heading a charitable foundation.