player prop betting and injury

Hey, I was wondering how do sports books grade player prop betting.  I've read the rules but can't find anything specific about what happens if a player gets injured during the game.  Let's say you have desean jackson +8.5 vs steve smith in receiving yards in yesterdays game.  Desean gets injured after one catch for 9 yards.

Is the bet void since desean didn't play the rest of game? 

I don't know exactly, but as long as the player plays at least one snap I don't think injury can void that. Only if the injury rules the player out before the game....

Different books have different rules and most will conform to the rule that screws you and just  gives them the money. It's not like there is a regulatory body to inforce rules. But from my previous experiences, a scratched player is a no bet but one who starts makes the action live.