The Broncos finished the regular season as the top seed in the AFC conference, but lost their opening playoff game to the Baltimore Ravens.
The linebacker told the team's official website: "I feel like we have a way better team than we had last year.
"I think we have one of the best interior defensive lines in the game right now. And we haven't even stepped foot on the football field, we've still got a long way to go.
"We just want to be the best team we can possibly be, and we know if we can do that, that will be more than enough."
Miller recorded 18.5 sacks, six forced fumbles and an interception last year.