A lot of the Broncos Defensive success this season was due to the work that Vickerson, Bannan, Wolfe, and Unrein did to stop the run on the interior DL. I doubt that the Broncos FO believes that spending a 1st round draft pick on another run-stopping DT is a priority this offseason.
That being said, if Kawann Short is available at #28, he presents a ton of value.
I think the top 3 value picks at #28 for the Broncos (as their roster is right now would be):
I suspect the Broncos will be heavily pursuing CB in Free Agency in order to alleviate pressure to pick one in the 1st round of the draft.