Question:
I would just like to clarify that all players on the field 
have the option of being recievers in a play.  
The 8 on 8 rules state this on page 3 under eligible receivers, 
and I understand that this would mean that the tackle sensors 
could not be covered.

Answer:
You are correct, all players are eligle receivers.
However, if a player has its tackle sensor covered at any time
during a play, it is ineligible to advance the ball.