In addition to what Gord said, if the situation does arise you have little alternative but to draw to the player's attention that he has just incurred a penalty. Failure to do so could be construed as a breach of Rule 1-3 Agreement to Waive Rules and could result in your own disqualification. If you are his marker say that without including the penalty you will be unable to sign his card.

Good luck in the Championship. Go get 'em!