After losing four starters during the first three days of unrestricted free agency, the Broncos' depth took a hit after defensive lineman Mitch Unrein signed with the San Diego Chargers and tight end Jacob Tamme joined the Atlanta Falcons on a two-year contract.

Unrein's two-year deal for a reported $1.9 million brings down the curtain on a local success story. An Eaton, Colo. native, he matriculated at Wyoming before eventually latching onto the Broncos' practice squad in 2010. He stuck on the 53-man roster a year later and persisted through heavy turnover on the defensive line, even seeing some work as a fullback, from where he caught a 1-yard touchdown pass against the Tampa Bay Buccaneers during a Dec. 2, 2012 game.

Unrein was caught in a squeeze as the Broncos converted to a 3-4 alignment. Executive Vice President/General Manager John Elway said on March 11 that the Broncos would like to bring back Unrein. But at 306 pounds, he wasn't the best scheme fit for the new 3-4 alignment: a bit too small to be the nose tackle and not a natural skill set fit to be a 3- or 5-technique defensive end.

The Broncos are left with Sylvester Williams and Marvin Austin as the likely nose tackles among players on the current roster. Derek Wolfe, Malik Jackson and March 14 pickup Vance Walker project as the top three defensive ends in the 3- and 5-technique rotation.

For Tamme, the Falcons could represent an opportunity for more playing time. Although he became a special-teams standout the last two seasons, his offensive repetitions decreased, and he played in just 24.5 percent of the snaps in 2014. The commitment the Broncos made to Owen Daniels and Virgil Green last week left him facing another year as the No. 3 tight end if he had returned.

Tamme caught 86 passes for 848 yards and five touchdowns in three seasons with the Broncos. Fifty-two of the catches and 555 of the yards came in 2012, when he split time at tight end with Joel Dreessen.

As Tamme departed, he praised the Broncos.

It would come as no surprise if the Broncos add another tight end in the next few weeks or via the draft. Their current complement of possibilities to work behind Daniels and Green includes Dominique Jones, who played four offensive snaps last year, and recent signee Joe Don Duncan, a 6-foot-4, 270-pound physical freak who had 35 bench-press repetitions at last year's Scouting Combine but was also a fundamentally sound, agile receiving target at Dixie State, where he was a Little All-American.

Duncan went undrafted and unsigned after the draft because of a foot injury that lingered from the end of his senior season through the entire pre-draft process, but if he is healthy, could be an intriguing high-ceiling prospect.