The Chicago Bears finished in last place in the NFC North last season with a 6-10 record, but despite a difficult season saw some major improvements especially on the defensive side of the ball. Bears first-year head coach John Fox took a Bears team that finished 30th in the league in yards allowed in 2014 to 19th in the league this past season.

Chicago still clearly struggled on defense, but showed a strong improvement under Fox in his first season. Bears general manager Ryan Pace has been making some significant moves this offseason to bolster the defensive side of the ball, including landing linebackers Danny Trevathan and Jerrell Freeman.

The Bears continued to add depth to their linebacker core on Monday, retaining linebacker Sam Acho on a one-year deal. In his first season in Chicago, Acho recorded 60 tackles, three tackles for a loss, and forced a fumble. The former fourth-round draft pick started in seven games for the Bears at outside linebacker, and not only brings depth to the linebacker position but was effective of special teams in 2015, recording eight tackles.

The 6-foot-3, 257-pound outside linebacker posted his best season in his rookie year with the Arizona Cardinals recording seven sacks, five tackles for a loss, and four forced fumbles. Acho turns 28-years-old at the beginning of the 2016 season, and could prove to be strong piece in Chicago's defense, as he has shown the ability to get it done in the league.

Chicago's front office has made some major decisions this offseason including letting veteran running back Matt Forte walk in free agency, but have also retained multiple players that proved to be productive last season such as tight end Zach Miller and defensive lineman Mitch Unrein.

The Bears have clearly upgraded the defensive side of the ball with the moves they have made in free agency this offseason, but are not done as many expect them to target defense in the early rounds of the 2016 NFL Draft. The Bears do have needs on their offensive line this offseason, but will surely look to bolster both their pass rush and secondary, as they look to continue to build a strong defense that can excel under Fox.