FIFA president Sepp Blatter has admitted the stadium in Sao Paulo where the opening game of the World Cup will be played may not be ready until 14 April 2014 and that there is currently no 'Plan B'.
Two workers died at the Itaquera Corinthians in Sao Paulo last week when a crane collapsed onto the stadium.
The tragedy meant delivery of the arena would never be achieved on target before the end of 2013.
But with the stadium due to host the first game on 12 June, Blatter's latest assessment of "April 14th or 15th" means tournament organisers face a race against time to make sure their preparations are complete.
"We believe it is a question of trust that it will be done," he said of the Sao Paulo building work.
"For the time being, there is no Plan B.
"What FIFA can do, we can now ask God, Allah, or whoever, that no more accidents will arise in connection with the World Cup.
"It is the only thing we can do and hope the reconstruction of the site can start as soon as possible.
"But for the time being, it is still under investigation (after the accident)."
FIFA secretary general Jerome Valcke later told reporters the mid-April target was for the first match to test the stadium operations.
FIFA has had to compromise on its original demand that all 12 World Cup stadiums should be delivered by the end of 2013, to allow for a minimum three test events.
Watch the World Cup draw live on Sky Sports 1 HD and Sky Sports News HD from 4pm on Friday.