Dumb substitution question

[Breeze]

I say it's a dumb question becaue I'm sure the answer was right in front of my nose, but it's late so I missed it:

I'm playing a game, and I want to change my quarterback. So I make the substitution, no problem. But it doesn't stick. I seemingly have to make the change before every play. How do I get the change to stick?

[garysorrell]

I think there is a box or something you select that makes changes stick....I think it says 'Persistant Changes'

Its on the play select screen, to the right above the box with players names

[Breeze]

Yeah I saw that, but I couldn't get it to work.  Am I supposed to click the box first, then make the sub?  Or the other way around?