But I think its not necessarily a balance between time on the field and stats.

If players are consistantly wearing down every game on defense, the stats degrade exponentially. Its not a straight line graph. It gets worse as the season goes on.

I think the defense will improve a great deal, because I think the offense will improve a great deal. Martz will call pass plays with hot receivers if he sees 8 or 9 in the box, and he will do this on any down and distance. There will be no more of this running plays on 1st and 2nd down with little or no gain, then a pass play with only one receiver on a route for a whole game. It will be mixed up a great deal more than it was at the beginning of last year.