In an effort to bolster that defense, the Falcons made a schematic shift in 2014, but the transition hit a major snag when linebacker Sean Weatherspoon was lost for the season to a torn Achilles tendon.
That injury has left the Falcons scrambling to fill a huge hole in the middle of the defense. In an effort to help fill that void, the Falcons turned to the free-agent scrap heap at the position.
The thing is, in doing so the Falcons may have done a lot more than just add some depth and experience to their linebackers.
If things break right, the Falcons may just have stumbled upon the player who could solidify the group and help the Falcons get back into the playoff chase.
The 27-year-old tallied 63 tackles in 11 games for the Colts last year before a knee injury (that required microfracture surgery) ended his season early.
And that's been the story with Angerer, at least for the past two seasons. Over the past two years, Angerer has missed numerous games and has been limited in countless others, to the point where the Colts pulled Angerer from the starting lineup.
However, as Tom James of the Terre Haute Tribune-Star pointed out, some of Angerer's struggles were borne of good intentions:
Remember, before the offseason acquisition of D'Qwell Jackson, the inside linebacker spot in Indianapolis next to Jerrell Freeman has been a revolving door of disappointment in recent years.
Back in 2011, however, it was a different story with Angerer. The former Iowa standout started all 16 games for the Colts that season, finishing fourth in the NFL with 148 tackles.
Granted, expecting that sort of performance from Angerer in 2014 may lean toward the delusional side of optimistic, but you can't fault the Falcons for hoping against hope.
After all, right now the Falcons can use all the help they can get.
Paul Worrilow, who is locked into one of the starting spots inside for the Falcons, posted solid stats as a rookie last year. Those stats didn't tell the whole story though, as Worrilow graded out as the 10th-worst inside linebacker in the NFL, according to Pro Football Focus (subscription required).
Fellow second-year pro Joplo Bartu, who filled in for Weatherspoon on the weak side in 2013, graded out well against the run, but Bartu struggled in coverage and is a bit on the small side for a 3-4 inside linebacker.
There's also rookie Prince Shembo, who will be afforded an opportunity to start in training camp, according to what head coach Mike Smith told D. Orlando Ledbetter of The Atlanta Journal-Constitution: "We’ve got Prince Shembo, who we are very excited about. He’s picked up the system very well. He doesn’t have any experience, but we will get him a lot, I can assure you that, in the preseason."
There's some talent there, but it's a group that would have benefited from the steadying influence of a veteran like Weatherspoon.
Now, perhaps Angerer can be that steadying presence.
Everything will, of course, hinge on Angerer's ability to stay healthy, something he's had more than a little trouble doing the past couple of seasons.
However, it's a hopeful time of year, so let's assume he does.
At the very least, a healthy Angerer gives the Falcons flexibility in subpackages. Angerer was a more than capable coverage linebacker when last we saw him at 100 percent, ranking 12th in that regard at his position for PFF back in 2011.
If he really can recapture past form, then Angerer could serve as much more than just depth. At his best, Angerer was a slightly more rangy Worrilow. Not the most physical of presences inside, but a player who compensates for a lack of elite athleticism with toughness and strong football instincts.
That's far from a sure thing, of course. After all, it's been a while since we saw "that" Pat Angerer.
Still, the Falcons were reeling from the Weatherspoon injury, and Angerer's signing represents what's essentially a no-risk proposition for the Falcons.
Even if Angerer plays the best football of his life, it isn't going to magically fix all the Falcons' defensive problems in 2014, but assuming Angerer can stay on the field, he should at least help shore up the second level of the defense.
And that, in and of itself, could go a long way toward getting the Falcons back in the NFC South race in 2014.
Gary Davenport is an NFL Analyst at Bleacher Report and a member of the Fantasy Sports Writers Association and the Pro Football Writers of America. You can follow Gary on Twitter @IDPManor.