When Head Coach Gary Kubiak took his first head-coaching job with the Houston Texans in 2006, he brought the 4-3 defense the Broncos used at the time with him.
But by 2011, Kubiak had Wade Phillips as his defensive coordinator -- and Phillips' trademark 3-4 scheme in place. The Texans responded with their first division-title winning team, and Kubiak was converted.
"I've become a believer. I think when your roster is set for a 3-4 defense, you've obviously got a lot more athletes as far as guys that can run -- linebackers on your football team, and you're a little bit heavier in that position. I think it helps you special-teams wise," Kubiak said.
"Does that mean you're always going to be that way? No. Sometimes head coaching, maybe it's a coordinator that you're chasing to try and put on your staff, and you feel good about him and he's a 4-3 guy. But I know from a roster standpoint, I think a 3-4 gives you a lot more athletic guys number-wise at the linebacker position that can help you be a better special-teams unit."
That's how the recently signed Reggie Walker could fit into the mix, and why the Broncos re-signed Steven Johnson, even though 2014 rookies Todd Davis, Lamin Barrow and Corey Nelson are in the mix.
Two areas of the front seven will bear close monitoring in the next few months.
The intention is for Brandon Marshall and Danny Trevathan to eventually take the two inside linebacker positions, but the Broncos might not have them for organized team activities as they complete recovery from the injuries they suffered last season.
Marshall played through the postseason loss to Indianapolis with a Lis franc injury he suffered four weeks earlier against the Chargers. The injury limited his repetitions, which he shared with Davis.
Marshall emphasized after the season that it was not as severe as the one suffered by Ryan Clady in 2013; the Pro Bowl left tackle was still bothered by it through much of the 2014 season. But given the tricky nature of Lis franc injuries, it's wise that Marshall take as much time as possible to ensure recovery from the injury.
Trevathan had three separate fractures around his left knee, suffered in the preseason, the Week 6 win over the New York Jets and the Week 15 win at San Diego.
Both "are going to be fine," Kubiak said, but in the meantime, their work could be limited.
"Obviously it's going to be a mental offseason for both of [those] guys more than anything," Kubiak said. "But I'm hoping through a lot of the walkthroughs and things that we do that they can be a part of some of that."
If Marshall and Trevathan don't participate in OTAs, that leaves opportunities for Davis, Nelson and Barrow.
"A lot of times through stuff like this, you'll find some younger players that you may never know you were going to find," Kubiak said. "So it will just give other guys an opportunity, but we'll continue to move forward with what we do."
The installation of a 3-4 alignment forced changes to the Broncos' No. 2-ranked defense.
Sylvester Williams is in the mix to start at nose tackle, and Derek Wolfe and Malik Jackson project as the defensive ends. But Kubiak and Phillips plan to make liberal use of other defensive linemen, which includes defensive end Vance Walker, potential nose tackle Marvin Austin and others on the roster, including some who could arrive via free agency or the draft.
"I think we're going to have a rotation," Kubiak said. "I can't sit here and tell you, 'Here's our guys; that's it.' I think we'll be a rotation-type group. If you look at most fronts, defensively, in the National Football League right now -- if you're a 3-4 team people are playing five, six guys a game and they're rotating them. [The] 4-3 teams are playing seven, eight guys.
"I think that's extremely important, especially if you're playing no-huddle tempo-type teams. So I think we've got to put a good group together. I know one thing: we have one hell of a coach in [Defensive Line Coach Bill] Kollar. He'll get the most out of them. So it's a priority right now. We need to get better there, also, so that is obviously a priority as we move forward, but I think we'll play a lot of people."