I'm not terribly upset that Paps is gone, but mid-tier? I have to object to that. He's 31 of 35 in saves, which is bang on his career average. His WHIP is almost identical to his career average. His K/BB is a little better than his career average. And as always for the last 6 years, he's been perfectly healthy.
Who exactly, besides Rivera, are you rating above Papelbon, and by what statistical measures?