There can never be a rule that would judge if a player is "faking" an injury. However, for sake of player safety, just like targeting is for player safety, that player should at least sit out for the drive and not allowed back until he has been evaluated by a doctor. The idea of playing through an injury, no coach is going to put up with that, they would be a weakness for the team.
The most obvious action should be that once an injury has been signaled, the players stay in place with no other substitutions and the coach is not allowed to communicate with non-injured players on the field until play continues. I think Ole Miss got 14 free time outs in the second half of our game.