Quote Originally Posted by Guiness View Post
Are the guards often mic'd for some reason? Is he saying the opposing team could get access to a recording of his calls at the line? I can see where that would force the O to change up the calls a lot.
The CBA has two provisions for mic'ing players:
One allows NFL films to chose players to mic for gathering sound to use in its films. No player is required to do it more than 4 times in the regular season, but there is no limitation in preseason or postseason.

The second allows mics in o-linemen's pads for sound during TV broadcasts. This was modified later to require mics in the pads of either both starting guards, or the starting and backup center. I've heard Sitton and Lang comment about it in the past.