During the Game

Rosters - Who's who on the field? Include small bios and uniform numbers of most of DC's players. Emphasize their role when they play.
Rules - What's a foul? Keep it simple. Q: I saw a foul, why wasn't it called? A: The ref is blind, or perhaps advantage is being played.
Offside Law - Okay, what the hell is this offside thing? Quick, simple discussion. Mention that there are complications like passive vs. active, but essentially the AR flags it so you don't need to worry about it.
Tactics - What's going on? A brief orientation to explain what to look for tactically. Keep this very simple, but mention things like space, counterattacking, possession, pressure, etc...
Evaluating the Game - Are we winning? How to tell if United is playing well even if they haven't gotten a lead yet. Or, how to tell that they're struggling.