An undrafted rookie free agent cut by the Houston Texans, Unrein was added to the Denver Broncos practice squad in 2010. He grew up in the small town of Eaton, Colorado about 70 miles north of Denver.
Unrein, 28, worked his way onto the active roster and was a steady contributor during his six years in Denver. However, a healthy Unrein was inactive for nine of Denver’s 17 games last season, including the team’s playoff loss against the Indianapolis Colts. He played just 46 snaps for the Broncos on defense in 2014.
"I’m looking forward to it," Unrein said. "That actually played into it quite a bit. I knew the San Diego Chargers. I knew what their program was because we had to compete against them every single year. I knew that they were a tough team. They would always give us problems. So I knew they were going to be a competitor, and we’re looking forward to being a top competitor this year.
"It will be nice to get some payback this year."
Familiarity also played a role in Unrein’s decision. He knew Chargers head coach Mike McCoy from McCoy's time as an offensive coordinator in Denver. Unrein was used as a fullback at times in goal-line situations for the Broncos, and Unrein to know McCoy while learning what packages he would be used in on offense during game week.
In 2012 with McCoy serving as Denver’s offensive coordinator, Unrein saw action as a fullback in short-yardage situations. He caught a 1-yard touchdown pass in a game against Tampa Bay to become the first Broncos defensive lineman in team history to catch a touchdown pass.
Unrein will go up against another familiar face in practice with former Denver guard Orlando Franklin also joining the Chargers in free agency. At 6-foot-4 and 306 pounds, Unrein serves as a backup for Kendall Reyes and could see some time on special teams.
"I feel like I’m one of those guys that learns the position, learns the technique that they want me to do," Unrein said. "That’s what I pride myself on -- taking what the coach says and applying it to my game. I might not be the quickest guy, but I definitely feel like this is a good fit for me because I like a lot of movement. It keeps the offensive line guessing.
"As long as I can get on the field more than I did in Denver last year, I’ll be a happy camper."
Unrein’s wife is a two-time Olympian trap shooter Corey Cogdell-Unrein. She earned a bronze medal in the 2008 Beijing Olympics, and just missed the finals in the 2012 London Olympics.
Unrein said the two met on a blind date a little over four years ago. The couple celebrated their first wedding anniversary over the weekend.
"She’s teaching me how to shoot better," Unrein said. "I grew up shooting waterfowl, pheasant -- stuff like that, but never really competitive shooting like she does. So there’s a lot of little technical things that she has taught me, and I’ve become a better shooter.
"It’s very humbling when you’re a guy. Usually when you’re a guy, you teach your significant other how to shoot, not the other way around. So I definitely had to swallow my pride. You just don’t feel as manly when a woman is teaching you how to shoot, but I’m a good sport about it."