In 2013, the Bears hired Marc Trestman to help fix Jay Cutler. And while Cutler showed improvement in an injury-shortened first season -- he ranked 13th in Football Outsiders' value-per-play metric -- he threw a league-leading 18 interceptions in his second season and the Bears went from 8-8 to 5-11.

Trestman was fired and his final stat line fell well short of expectations: A 13-19 record and a point differential of -156. It's why former Bears linebacker Lance Briggs, who played for Trestman and Lovie Smith before him, thinks Trestman never should have been hired.

"Everybody in Chicago knows that Trestman shouldn't have been here," Briggs said Monday during an interview on the "Spiegel and Goff Show" on CBS Sports Radio. "He shouldn't have been a coach here. Not to take anything from him, he's a great coach, but he wasn't a coach the Chicago Bears should've had. That's just the truth. I was one of the guys, (Charles) Peanut (Tillman) was one of the guys that had to live through that those next two years (in 2013 and 2014), where if it ain't broke, then what are you trying to fix?"

By comparison, Smith spent nine seasons in Chicago and went 81-63, including 10-6 in his final year with the club. He also led the Bears to the playoffs three times, and to a Super Bowl appearance in 2006.

"I know we wanted to improve our offense, but we had a team that .... should've been in the championship game. We went 10-6 and should've been in the playoffs," Briggs continued. "The year before, we were in the (NFC) championship game. So what exactly is it that you really need to fix about the team? We had great leadership and things like that, and you saw things kind of go in a different direction. It's not the way you want to end your career, but I still had great relationships, from the coaches to the players and the city."

The answer is Jay Cutler. Of course, things went so far off the rails in Trestman's second season, that he actually benched Cutler for Jimmy Clausen. That probably qualifies as the nadir of Cutler's career, though he bounced back nicely last season under offensive coordinator Adam Gase, who is now the Dolphins' head coach.

"(The new staff is) innovative. Smart," Cutler said in April 2015, shortly after Trestman was replaced by John Fox, who brought Gase with him from Denver to Chicago. "It's a joy to work with these guys right now."

Cutler would completed 64 percent of his throws last season, with 21 touchdowns, 11 interceptions and a career-best 92.3 passer rating. He also ranked ninth among all quarterbacks in value-per-play, ahead of ahead of Cam Newton and Derek Carr.

Whether Cutler can replicate his success is one of the biggest questions facing the Bears. Gase is gone, replaced by quarterbacks coach Dowell Loggains, so there is some consistency there. Meanwhile, Trestman is the offensive coordinator in Baltimore, and Smith is in his first season as the coach at the University of Illinois.