NFL Player Props - Flacco v Roethlisberger

[Waiting4Godot]

So.. let's say a book has a player v player prop up for Flacco and Roesthlisberger and Ben doesn't actually play. If you took that bet for Flacco to win, how would/should they grade it?

I looked at the rules page, but didn't see anything specific to player props.

[SpiderMonkey]

Player props require the sides to play. Usually stated below the line.