Fifa should complete tests on the candidates standing in the election to succeed Sepp Blatter as president, says global players' union Fifpro.
The organisation wants four tests to be done, which include a check on their human rights and governance records.
Uefa president Michel Platini, Prince Ali of Jordan, ex-Fifa executive Jerome Champagne and former player David Nakhid have submitted candidacy bids.
All bids have to be submitted by Monday's deadline.
|Fifpro's Four Criteria for Fifa Presidential Candidates|
|Proven capacity to drive reform of a democratic and politically complex body||Governance Record|
|Human rights record||Understanding of the game as a sport and business|
Fifpro said the future leader of Fifa should be an "impeccable figure" who has "a track record of being able to lead".
In a statement, it added: "Eliminating even the slightest perception of conflict of interest will be critical part of a robust reform, as opposed to the charade of self-regulation that has damaged the image of the world's most popular sport.
"A clean break from the past is essential for Fifa to climb out of the toxic pit which continues to produce serious accusations of corrupt behaviour on almost a daily basis."
Platini is currently serving a Fifa ban as football's governing body investigate a £1.35m payment the Frenchman received from Blatter.
Asian Football Confederation (AFC) Sheikh Salman Bin Ebrahim Al Khalifa could also stand, but has faced repeated accusations of being complicit in human rights violations against pro-democracy protestors in Bahrain in 2011.
Sheikh Salman has always denied the accusations.
Former Tottenham defender Ramon Vega is another who is considering standing as a candidate after stating he "comes without baggage".