Editor’s note: This is the sixth in a series of NFL draft previews as it relates to the Broncos. Previous previews: quarterbacks, running backs, wide receivers, tight ends and offensive linemen. Today: Defensive linemen. Broncos’ in-house offseason moves: Signed Malcolm Roach to a two-year deal, signing Angelo Blackson to a one-year deal, did not tender Jonathan Harris. Under contract: Zach Allen (two years), Matt Henningsen (two years), Roach, Eyioma Uwazurike (two years), D.J.