Getting beyond that what happens when an opposing player's assignment is to make a hole for his RB or QB to complete the route and the only way he can do it it is to knock the defender out of the game? Would he go lighter on Sam so he doesn't get the backlash if he does knock him out? It would almost be like beating up a girl. Players shouldn't have to consider such things.
The lawyers and their paid medical expert witnesses will show the NFL if there is a way, this can happen.