The head of global soccer players' union FIFPRO criticised FIFA's lack of consultation with stakeholders before proposing its biennial World Cup plan, saying it raised serious concerns by adding more pressure to the international calendar.
World soccer's ruling body announced a feasibility study on holding the men's and women's World Cups every two years instead of four - a proposal which has been met with strong opposition from European governing body UEFA and South America's CONMEBOL.
FIFPRO general secretary Jonas Baer-Hoffmann called for a wider discussion around the proposals, saying even the reforms which merit implementation, such as having fewer international breaks, would not work without consultation with stakeholders.
"There is a chance of a real breaking point in football around this if it is not funnelled into a proper process," Baer-Hoffmann was quoted as saying by the Times on Wednesday.
"That requires some leadership which I haven't seen around this question in football for the last few years, to actually step away from the interests of your own competitions and have a broader discussion.
"There is a lot of lost trust between institutions in football and therefore we are on combative lines before any details are exchanged."
FIFPRO on Tuesday criticised FIFA's "flawed process" in expanding the international calendar, saying that any reforms must include safeguards for players' health and facilitate the development of both men's and women's football.