I was just over on Bleacher Report reading their NFL 1000 series and they had Dan Koppen ranked as the 17th best center in the league.
Was it just me or was Dan Koppen the biggest unsung hero on the Broncos offensive line (maybe even the whole team) last season? I'll be quite sad if he isn't resigned by us, it seems like he could be a valuable (and above average) swing player on the interior of our line. A starting interior of Beadles, Walton, and Vasquez and backups of Kuper, Blake, and Koppen seems quite favorable.
I can only think of a handful of reasons why he may not be resigned. 1) Were flush with players and tight on the salary cap now that the draft is over, I'm not really sure how to estimate what kind of salary he would command or even what he made last year. 2) The Broncos are trying to get younger and seem excited about the development of Phillip Blake, so maybe they're saving roster spots to see which of the young bloods come out on top during training camp.
However, personally, I believe the positives to having Koppen signed, for at least this season, far out weigh the potential negatives.