Workers of the Arena Corinthians play a football match as part of May Day celebration on May 1, 2014, in Sao Paulo, Brazil. The Arena Corinthians will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO / NELSON ALMEIDA

Workers of the Arena Corinthians play a football match as part of May Day celebration on May 1, 2014, in Sao Paulo, Brazil. The Arena Corinthians will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO / NELSON ALMEIDA

Workers are seen at the Arena Corinthians on May 1, 2014, in Sao Paulo, Brazil, which will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO / NELSON ALMEIDA

A worker is seen at the Arena Corinthians on May 1, 2014, in Sao Paulo, Brazil, which will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO / NELSON ALMEIDA

Workers are seen at the Arena Corinthians on May 1, 2014, in Sao Paulo, Brazil, which will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO / NELSON ALMEIDA

Workers of the Arena Corinthians line up before play a football match as part of May Day celebration on May 1, 2014, in Sao Paulo, Brazil. The Arena Corinthians will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO / NELSON ALMEIDA

Workers of the Arena Corinthians play a football match as part of May Day celebration on May 1, 2014, in Sao Paulo, Brazil. The Arena Corinthians will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO / NELSON ALMEIDA

Workers of the Arena Corinthians play a football match as part of May Day celebration on May 1, 2014, in Sao Paulo, Brazil. The Arena Corinthians will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO / NELSON ALMEIDA

Workers are seen at the Arena Corinthians on May 1, 2014, in Sao Paulo, Brazil, which will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO / NELSON ALMEIDA

Picture of the Arena Sao Paulo, stadium of the Brazilian team Corinthians, taken on April 15, 2014 in Sao Paulo. The Arena de Sao Paulo will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO/Miguel SCHINCARIOL

Picture of the Arena Sao Paulo, stadium of the Brazilian team Corinthians, taken on April 15, 2014 in Sao Paulo. The Arena de Sao Paulo will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO/Miguel SCHINCARIOL

Picture of the Arena Sao Paulo, stadium of the Brazilian team Corinthians, taken on April 15, 2014 in Sao Paulo. The Arena de Sao Paulo will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO/Miguel SCHINCARIOL

Picture of the Arena Sao Paulo, stadium of the Brazilian team Corinthians, taken on April 15, 2014 in Sao Paulo. The Arena de Sao Paulo will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO/Miguel SCHINCARIOL

Picture taken at the Arena Sao Paulo, stadium of the Brazilian team Corinthians, on April 15, 2014 in Sao Paulo. The Arena de Sao Paulo will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO/Miguel SCHINCARIOL

Picture of a changing room of the Arena Sao Paulo, stadium of the Brazilian team Corinthians, taken on April 15, 2014 in Sao Paulo. The Arena de Sao Paulo will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO/Miguel SCHINCARIOL

Picture of a changing room of the Arena Sao Paulo, stadium of the Brazilian team Corinthians, taken on April 15, 2014 in Sao Paulo. The Arena de Sao Paulo will host the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12. AFP PHOTO/Miguel SCHINCARIOL

Picture taken on January 20, 2014 showing the damages (L) cause when a crane fell across part of the metallic structure of the Arena de Sao Paulo stadium --Itaquerao do Corinthians-- almost two months ago, and which is still under construction, in Sao Paulo, Brazil. The Sao Paulo Arena Corinthians, which is due to hold the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12, will only be ready in mid-April following an accident in November which killed two construction workers. The fatal accident has put back pre-tournament testing until mid-April. AFP PHOTO / Miguel SCHINCARIOL

Picture taken on January 20, 2014 showing part of the damages cause when a crane fell across part of the metallic structure of the Arena de Sao Paulo stadium --Itaquerao do Corinthians-- almost two months ago, are the works still being done, in Sao Paulo, Brazil. The Sao Paulo Arena Corinthians, which is due to hold the opening match of the Brazil 2014 FIFA World Cup between Brazil and Croatia on June 12, will only be ready in mid-April following an accident in November which killed two construction workers. The fatal accident has put back pre-tournament testing until mid-April. AFP PHOTO / Miguel SCHINCARIOL

Members of FIFA and the 2014 World Cup Local Organizing Committee makes an inspection tour of Arena de Sao Paulo stadium, in Sao Paulo, Brazil, Monday, Jan. 20, 2014. The commission started today an inspection tour of stadiums in host cities across Brazil. (AP Photo/Nelson Antoine)

View of the Arena de Sao Paulo stadium, in Sao Paulo, Brazil, Monday, Jan. 20, 2014. Members of FIFA and the 2014 World Cup Local Organizing Committee started today an inspection tour of stadiums in host cities across Brazil. (AP Photo/Nelson Antoine)