Mullahs had better pray that it turns out to be a boring game, 0:0 draw with no exciting plays. Either a stunning victory or a humiliating defeat could set off crowds to a frenzy.
Some of the greatest "football" riots happen after a nil-nil tie. You have a bunch of hooligans ginned-up (can they do that in a Muslim country) and taunting the other team since the crack of dawn. If neither favorite team cannot settle their "who's better / who's best" grude-match on the field, they tend to take care of it themselves.
There's a lot of misplaced pride invested in a bunch of people who can bop what used to be an inflated goat stomach off their heads.