The Atlanta Falcons have parted ways with offensive coordinator Steve Sarkisian, defensive coordinator Marquand Manuel and special-teams coordinator Keith Armstrong as part of sweeping changes following a 7-9 season.

Coach Dan Quinn will serve as defensive coordinator moving forward, the team announced Monday.

"All three of these men are excellent coaches that I have a lot of respect for," Quinn said in a statement. "While these are difficult decisions, we know we have a group of players here we are excited about and in order for us to consistently play true to our identity in all three phases we thought we needed some changes."

Former Seattle Seahawks offensive coordinator Darrell Bevell is considered the favorite to become the Falcons' next OC and will interview with the team later this week, a source told ESPN's Adam Schefter. Bevell, 48, coached on the Seahawks' staff with Quinn and was previously the offensive coordinator for the Minnesota Vikings.

Steve Sarkisian was not able to elevate the Falcons' offense and is out. AP Photo/John Bazemore

Former Tampa Bay Buccaneers coach Dirk Koetter is also being considered for the offensive coordinator role, according to multiple sources. Koetter previously held that role with the Falcons from 2012 to '14, and quarterback Matt Ryan always has been a big supporter of Koetter.

Although there had been speculation about the changes for a while, Quinn had vowed not to make any decisions until the conclusion of the season.

Sarkisian, a first-time NFL coordinator, held the role for two seasons after replacing Kyle Shanahan, now the coach of the San Francisco 49ers. Sarkisian spent his first season attempting to carry on the same outside-zone scheme Shanahan implemented and then added his own wrinkles during the second season. However, Sarkisian wasn't able to elevate the offense to the Super Bowl-caliber level it had reached under Shanahan, despite having former MVP Ryan, Pro Bowlers Julio Jones and Alex Mack and playmakers such as Calvin Ridley, Austin Hooper, Mohamed Sanu and Tevin Coleman.

"Sark has shown he's a good coach and playcaller," Quinn said. "After evaluating the entire season, I decided it was necessary that we had a new voice and direction for our offensive unit. I have a ton of respect for Sark, both personally and professionally, and I appreciate all he's done during his time here."

Inconsistency and injuries along the offensive line, plus losing two-time Pro Bowl running back Devonta Freeman to a season-ending groin injury, didn't help Sarkisian's cause.

In early December, Sarkisian said he didn't feel the need to answer his critics.

"I never feel the need to validate myself to anybody outside of our building," Sarkisian said at the time. "I work for Arthur Blank, Thomas Dimitroff, Dan Quinn, and I worked for these players. And I do the best I can do for them every single day. One week doesn't change how I prepare or what I do. You put the work in. You feel good about the work. And when you do, you're able to go to sleep at night knowing you did your job.

"You always want to do better. There's always things that you wish you did better."

Manuel, who joined the Falcons four years ago as the secondary coach/senior defensive assistant, spent the past two seasons as the defensive coordinator. In 2017, the Falcons finished in the top 10 in both scoring defense and total defense for the first time since 1998. This season, they suffered a significant defensive drop-off. It didn't help when starting safeties Keanu Neal (ACL) and Ricardo Allen (Achilles) went down with season-ending injuries and star linebacker Deion Jones missed 10 games following foot surgery to repair a broken bone.

"Marquand is a talented coach and excellent teacher that I have coached with for a number of years," Quinn said. "I believe he should have the opportunity to call plays for a defense, so we have decided to allow his contract to expire so he can explore those opportunities."

Manuel spoke up for himself before the season finale at Tampa Bay.

"I know one thing: I've coached this defense to the best they've had in 20 years," Manuel said. "With that being said, everyone is evaluated, which is part of why we do this job. And things of that nature will take care of themselves, as they always will."

Manuel could find a new home quickly, particularly if close friend and former Seahawks coaching mate Kris Richard, now with the Dallas Cowboys, becomes a head coach. There is a belief around the league that Manuel could be Richard's defensive coordinator in such a scenario.

Armstrong just completed his 11th season with the team. He once interviewed for the head-coaching job held by Quinn. Asked about the coaching staff evaluation process last week, Armstrong responded, "I don't worry about that part of it. I go out and do my job and coach my ass off and let the chips fall where they may."

Said Quinn: "Coach Armstrong helped develop some really good players on our kicking units over his time here. Special teams has to be the gateway to the identity of our football team. In order to see that, we felt we needed a new voice and design. We wish Keith nothing but the best in the future."

Jones, the Falcons' six-time Pro Bowl wide receiver, addressed the possibility on Sunday of playing under another offensive coordinator next season.

"We're all professionals here. We control what we can control," Jones said. "That's not on us. But whatever happens, we're going to make the best of it regardless. We're going to do a great job transitioning or keeping the same coaches. It don't matter to the players. That's not our call. We're going to come in, we're going to put the work in ... and we're going to be the best version of us."

Quinn has a history of handling the defensive playcalling. He took over those duties from former defensive coordinator Richard Smith during the 2016 Super Bowl season.

It is unclear in which direction the Falcons want to go regarding a new special-teams coordinator.