Seems reasonable to me that you should be able to fly this flag at a World Cup match:

Earlier this week, a lawsuit was filed against FIFA in California over the body’s ban on supporters bringing the pre-revolutionary Iranian flag into World Cup stadiums. The Institute for Voices of Liberty, a Californian non-profit which describes itself as “dedicated to advancing freedom of expression” for Iranians, claimed in the filing that those who wished to fly the flag possess “protected symbolic and political speech.”