FIFA secretary general Jerome Valcke has played down the significance of a 12-day extension for the completion of redevelopment work to Rio's Maracana Stadium.

According to FIFA's website, the work had been scheduled to end on April 15, having initially been given a December 2012 deadline.

But the world football governing body reportedly shifted the date for a fourth time to April 27 following a meeting with Brazil's 2014 World Cup organizing committee and sports minister Aldo Rebelo on Wednesday.

"I don't know where you got April 15 from," Valcke said during a press conference on Thursday, denying any change to the working schedule. "For FIFA the deadline has always been April 27."

Just two of the six stadiums selected to host June's Confederations Cup, considered a warm-up event for the World Cup a year later, are completed.

Maracana Stadium, which will host the final of both the Confederations Cup and World Cup, is still awaiting the installation of its fibre-glass roof and playing surface.

Valcke admits the iconic venue is the stadium that has caused most concern for FIFA. He revealed he will meet with Maracana consortium officials and local politicians on Friday to seek further assurances that the April 27 deadline will be met.

"There is no plan B for the Maracana. For this reason we need to have some answers tomorrow (Friday)," Valcke said.