Free agency is often about projection. How will a player fit in a different locker room? Will his skills translate to a new scheme with new teammates? And if you sign a backup to become a starter, can he make the leap?

With Virgil Green, some of those variables are off the table.

The Broncos know him well from watching his development over four years, from 2011 seventh-round pick to his starting stint at the end of the 2014 season after Julius Thomas succumbed to an ankle injury.

"Virgil's been a big part of what we do, and he's been one of those guys that [hasn't] necessarily been out in front of the scenes, but behind the scenes he's been a tremendous worker," Executive Vice President/General Manager John Elway said. "He's blocked; he's caught; he's been a tremendous contributor on special teams."

Green had the opportunity to join the Chicago Bears, but opted for familiarity -- inside and outside the building.

"We are established here. Going to Chicago, it would have to take a lot to get everything picked up and get out there, and I am comfortable here," he said. "I'm comfortable with Mr. Elway; I'm comfortable with the staff here. So for me, I just came out of playing in a real tough offense and learning a new offense isn't that big of a deal to me."

In the previous offense, Green started a career-high nine games last year. Itwas the Nevada product's best season to date, a year in which saw occasional work at fullback and H-back in addition to his snaps at tight end.

"I'm always down to do anything," Green said. "Fullback, I don't too much like fullback, but it's something that ''ve got to do and I don't mind playing at any position. You put me at guard, I'm going to do it. It doesn't matter to me."

Although Green played 297 fewer snaps than Thomas last year, he finished the season with a higher rating in ProFootballFocus.com's metrics -- plus-5.7 to Thomas' plus-5.4. Only one other tight end on the market this year had a higher PFF rating in 2014.

Effective run blocking had much to do with that; as the Broncos emphasized the ground game from Week 12 onward after Thomas' injury, Green was in position to drive off the line of scrimmage and spring C.J. Anderson for some of his best runs.

Even in Week 3 at Seattle, the Broncos leaned upon Green until he succumbed to a concussion. The reliance upon him was so great that multiple players pointed to his injury as a turning point in the game that forced it to change its game plan on the fly against the pressure-intensive Seahawks defense.

"I've taken advantages of opportunities that have come my way and I'm not much to complain about things. I just go out and do," Green said. "I feel like until I earn the right to say something, I just need to keep my mouth shut and do my job. To me, that's the only important thing."

His opportunities as a target in the passing game have been scant, and he didn't score his first pro touchdown until late in the Week 17 win over the Raiders last year -- on a pass fired by Brock Osweiler, which was also the first touchdown strike of the young quarterback's career.

But on that possession, the Broncos might have gotten a brief glimpse of their future. Osweiler found Green down the seam for a 38-yard gain to set up the 1-yard score. With a single high safety, Oakland's underneath coverage released Green into the open field, and he easily made the catch.

With the Broncos' weapons, that's what you want from the tight end: the ability to take advantage of a defense overplaying the outside receivers and the underneath option out of the backfield.

A play like that -- and the trust it can engender -- should lead to more opportunities, more confidence from the team in the player and, in turn, more confidence by the player in himself.

"I just want to be efficient and a guy that teams just don't have to say 'Oh, well, he's in; they're running,'" Green said. "I want to be a guy [of whom] teams say 'He's versatile; he can do all things; he can line up at fullback, slot receiver, tight end and be efficient at all those positions.'"

And the Broncos' belief that he can do that explains why they wanted Green back on a three-year deal: he was the best blend of quality and affordability under the salary cap, and he has untapped potential that more chances could unleash.