Construction company Odebrecht confirmed that a part of the roof at the Itaquerao will only be completed after the World Cup.
There was not enough time to install the glass covers that were supposed to be added to the stadium's roofing structure, so Odebrecht and local organizers decided to postpone the work until after the tournament.
Odebrecht said the missing covers will not affect fans watching matches in the stadium, although it appears from photos that more people would be covered from rain if they were in place.
Also Friday, the company in charge of 20,000 temporary seats needed for the opener said it successfully addressed all health and safety issues that had prompted prosecutors to threaten to halt work at the venue.
Odebrecht said in an email sent to The Associated Press that "the glass covers will only be installed after the World Cup" because "transparency studies" were still being finalized to make sure the covers can allow the passage of the proper amount of light needed to "preserve the pitch in good conditions."
The metal structures where the glasses have to be installed are in place but they will be empty by the time the nearly 70,000 fans and guests arrive for the high-profile opener between Brazil and Croatia on June 12. The venue will host five World Cup matches, including one of the semifinals.
Odebrecht said the roof itself is ready and guaranteed that the covers are not essential, even though they were part of the initial project.
The company had already said that not all fans in the temporary seats behind the goals will be fully covered from rain.
The local World Cup organizing committee said it was not a requirement to have stadiums with all of their seats covered.
"The architectural project of the Arena de Sao Paulo, as of the other 11 stadiums, is not intended to have 100 per cent of the fans protected from rain," the committee said in a statement. "That is only possible in stadiums completely covered."
FIFA did not immediately respond to a request for comment.
The Itaquerao is one of the three stadiums yet to be completed ahead of the World Cup. Late last year, two workers died after a crane collapsed while hoisting a huge roofing structure, causing significant construction delays at the venue that was expected to be ready by the end of last year.
In March, another worker died while installing the temporary seats there, prompting labour officials to halt construction and causing another delay.
On Thursday, prosecutors said they found health and safety irregularities at the Itaquerao and threatened to stop the installation of the temporary seats that are still missing. The company in charge of the work, Fast Engenharia, said Friday that it addressed all the problems pointed by prosecutors and dismissed the possibility of another work stoppage.
In his latest visit to Brazil last month, FIFA Secretary General Jerome Valcke said there was "not a minute" to waste if local organizers wanted to make sure the Itaquerao was ready for the opener.
Tales Azzoni on Twitter: http://twitter.com/tazzoni