Kaan Ayhan scored on the final kick of the match, and Turkey beat the United States 3-2 Thursday night for its only win of the World Cup.
The winner of Saturday's match will go on to the semi-finals to take on either Argentina or Australia, who also play Saturday.
The source said that they were told that their families would face "violence and and torture" if they did not sing the national anthem or if they joined any political protest against the Tehran regime.
US Soccer said it wanted to change the official flag for 24 hours to show "support for the women in Iran fighting for basic human rights" but always planned to go back to the original flag.
Declaration of a national emergency would give providers additional funding as well as more flexibility from regulations to deal with what call a "crisis."
Some of the most patriotic Americans packed Navy Pier Friday to cheer on the United States men's national soccer team as they squared off against their rivals across the pond in the World Cup.