Rivera, who has talked with eight different NFL teams about their head coaching positions over the last two seasons, had a three-year contract with the Bears that was set to expire next week. The NFC champions announced Monday he will not be back.
Head coach Lovie Smith had been pushing Rivera for head coaching jobs, now he's pushed him off his staff.
"It's just something that coach decided he was going to shuffle his staff and we'll go from there," Rivera said during a conference call.
Rivera said he wanted to return and was told a few days ago he wouldn't.
Was there a personality conflict with Smith?
"No, no, no, no, please. I don't think there is. I really don't," he said.
"I believe this is just a football decision and it was made. Emotionally, I'm disappointed in not getting the opportunity to come back in '07 because as I said at the end of the year after the loss that this is a football team that's headed in the right direction."
Smith, a defensive-oriented coach, insisted there no philosophical differences with Rivera.
"As much as anything, it's just a fit that we have and right now the direction I would like to go and the direction that Ron would like to go, we're going in two different directions," Smith said during a conference call.
"It's been my goal all along to help Ron, to do everything I could to get Ron an opportunity to get a head football coaching job and it's no more than that. We've tried to do that. Ron had a contract. I don't see it as a firing or anything like that. His contract expired and he wants to go in one direction, and I'd like to go in one. No more than that. "
Rivera was a linebacker on Chicago's Super Bowl champion team in 1986 and then led a defense that helped the Bears make the playoffs in back-to-back seasons. Chicago had trouble containing Indianapolis in the Super Bowl, losing 29-17 to the Peyton Manning-led Indianapolis Colts.
Rivera has been an assistant coach for 10 years in the NFL beginning as a quality control coach with the Bears in 1997. He spent five years with the Philadelphia Eagles as their linebackers coach and then the last three in charge of Chicago's defense.
The Bears led the NFL with 44 takeaways in the regular season, but the defense was slowed in the latter stages of the season after injuries to defensive tackle Tommie Harris and safety Mike Brown.
Smith did not elaborate when asked if there were things about Rivera's performance he did not like.
"Those are the things Ron and I talked about," Smith said. "We feel good about the things we did together during that time, but no more needs to be said about that. That's between he and I."
Rivera was a candidate last season for head coaching jobs in Green Bay and St. Louis. This year he talked with Pittsburgh, Miami, Atlanta and Arizona before the Bears started postseason play. After Chicago lost the Super Bowl, he interviewed for coaching vacancies at Dallas and just a few days ago at San Diego.
Smith said he would move quickly to replace Rivera. Linebackers coach Bob Babich is considered a top candidate.
Even though many NFL coaching spots are already filled, Rivera said he is confident he will get a job.
"The timing sometimes could have been better or it could have been worse. It is what it is right now," he said. "It's just something that's happened and I'm going to go from there."