Sometimes teams are not completely honest as far as the extent of injuries.  A team can get their team doctor to say that this player needs a full year to recover (even if it is not such an injury) just to get the player stashed in IR.
Kelly has not taken a single snap so far in practice or camp.  No way are the Broncos going to carry him on the regular roster.  He goes into IR.  Same with Jake Butt.