This is why Charlie has said (paraphrasing):
We need to get those five new defensive tackles in here A.S.A.P.! Three of them are over 300 pounds and one is right at it. We need to rotate in big bodies to keep our line fresh and wear down the offense.
And he's absolutely right. Green Mile's early exit was a big blow because what we have now is not going to be able to hold up for an entire game.
My guess is that we'll see three of the five shirts get ripped off after four fall practices.