The Chicago Bears have fired two members of their coaching staff after a disappointing defensive display from the team this season.

Linebackers coach Tim Tibesar and defensive line coach Mike Phair have both been relieved of their positions, but defensive coordinator Mel Tucker remains with the team.

The Bears conceded 478 points in the 2013 season, the second-worst tally in the entire league, but head coach Marc Trestman has stressed that their poor performance was not solely down to Tibesar and Phair.

"We thank Mike and Tim for their effort and dedication. They are men of high character and integrity. These are not easy decisions and we do not attribute our lack of success on defense to two individuals," he said in a statement.

"We need to improve in all areas defensively and that will be a focal point for us this offseason. The process starts with me as the head coach. Our search for a defensive line and linebackers coach has begun and we will be looking for the best candidates whose experience can bring the most out of our veteran and young players in both areas.

"Our team evaluation remains ongoing. We believe Mel is the right person to lead our defensive unit. He fully understands where we need to improve, has the skill set and leadership to oversee the changes that need to be made and to execute our plan to get the results we know are necessary."

Tibesar had only been with the Bears for one season, while Phair leaves after three years with the team.