Tagging Miller will create other contractual issues for the Broncos -- most notably, it would prevent the team from retaining quarterback Brock Osweiler unless it signs him to a long-term extension.
Miller was the No. 2 overall pick of the 2011 draft, picked one slot after Carolina QB Cam Newton, whom the Broncos face in Super Bowl 50 on Sunday. It will mark the first Super Bowl in which the players selected with the first two picks of the same draft will face each other.
Miller was named to his fourth Pro Bowl this season. He has 60 career regular-season sacks and added 2.5 more in the Broncos' win over the Patriots in the AFC Championship Game.
The Broncos used the tag on wide receiver Demaryius Thomas last offseason before signing him to a five-year, $70 million deal.