The stadium, which is due to host the opening game of the 2014 World Cup on June 12, suffered damage last week as a crane collapsed into the east part of the building, killing two construction workers.
Work on the arena is now set to continue past the target deadline of the end of 2013 because of the tragedy, with FIFA president Blatter hopeful that construction will be completed by April.
Organisers now face against a race against time to ensure that everything is ready for the tournament's curtain-raiser.
And Blatter admitted that FIFA do not have a plan B if the stadium is not finished in time.
"We believe it is a question of trust that it will be done," Blatter said.
"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)."
