By Chris Emma–

(CBS) Former Bears general manager Jerry Angelo has openly admitted that trading tight end Greg Olsen was a mistake. Of course, errors like that are why Angelo hasn’t run a front office since being fired from Chicago after the 2011 season.

But back in July 2011, then-offensive coordinator Mike Martz, who was also swifty dismissed by the Bears after that season, felt he didn’t have use for Olsen’s talents in his structured schemes. So the Bears traded Olsen to the Carolina Panthers for a third-round pick and made Kellen Davis their top tight end.

The Bears have seen widespread changes throughout their organization ever since dealing Olsen. They’re on their third head coach, third general manager and fourth offensive coordinator to take office at Halas Hall.

Meanwhile, Olsen’s about to play in the NFC championship game as a top target for the Panthers and Cam Newton, not Jay Cutler.

On the surface, it seems like the Bears really messed up by making this move. It’s hard to argue against that, especially when the man who pulled the trigger agrees, but all wasn’t lost for the Bears in the transaction.

In March 2012, recently appointed Bears general manager Phil Emery traded a pair of third-round picks to the Dolphins — one for 2012, the other for 2013 — in exchange for explosive receiver Brandon Marshall.

Emery was willing to take a risk on Marshall, who was at the time being traded for a second time. Having just been hired as Dolphins coach, Joe Philbin didn’t want Marshall’s disruptive influence around a new regime.

In turn, Miami shipped its 2012 third-round pick from Chicago off to San Diego for a third- and sixth-round selection, using those to pick tight end Michael Egnew and B.J. Cunningham. One pick after the Dolphins took Egnew, Emery selected Brandon Hardin, a third-round safety who never played an NFL game. One year later, Miami used Chicago’s other third-round pick to take Will Davis, a cornerback who has made little impact in his career.

In terms of pure talent, the Bears landed a steal in Marshall, who had 279 catches and 31 touchdown receptions in 45 games in Chicago. But when current general manager Ryan Pace was hired by the Bears in January 2015, he realized what led the Dolphins to trade Marshall three years prior.

Marshall’s volatile personality had run its course in Chicago, and it was time for the third trade of an elite talent. The Bears moved Marshall to the Jets for a fifth-round pick, a return that surprised all who have never endured Marshall’s presence in a locker room.

Now three-and-a-half years removed from trading Olsen to the Panthers, the Bears’ remaining value is safety Adrian Amos.

A bright scouting mind, Pace zeroed that fifth-round pick he acquired from a bold-but-necessary move of Marshall in on Amos, a promising safety prospect out of Penn State. As a rookie, Amos led the Bears in tackles with 108 and played in every game, including 1,027 of 1,030 defensive snaps.

While he had his struggles too, Amos became a steady presence for the Bears’ secondary. While his greatest needs for improvement come in pass defense, he brought stability to a unit that needed it, and he earned all-rookie team honors from the PFWA.

Trading Olsen was a clear mistake for the Bears. It was then — a fact lost in the arrogance of Martz and ignorance of Angelo — and the deal still is an error now. To the credit of Pace and his front office, the fifth-round pick of Amos in 2015 appears to be something the Bears can build with moving forward.

As fate would have it, not all was lost in trading Olsen.

Chris Emma covers the Chicago sports scene and more for CBSChicago.com. Follow him on Twitter @CEmma670 and like his Facebook page.