PITTSBURGH -- Following through on Mike Tomlin's promise to make changes after a first-round exit in the playoffs, the Steelers announced Thursday that offensive coordinator Randy Fichtner is out.

The Steelers will not renew his contract or the contracts of offensive line coach Shaun Sarrett and defensive backs coach Tom Bradley.

"I want to thank all three of the coaches for their commitment and dedication to the Pittsburgh Steelers," Tomlin said in a statement. "They have all played integral roles in our success and I am appreciative of their efforts. Personally, Randy and I have been in Pittsburgh since I hired him in 2007, but our relationship began well before that. He has been a friend of mine for years and wish his family nothing but the best, and I am eternally grateful for our relationship both on and off the field."

The organization is discussing a new contract with defensive coordinator Keith Butler, who, at 64, plans to go year-to-year before eventually retiring, a source told ESPN's Jeremy Fowler.

"I didn't anticipate being here in this position," Tomlin said in his end-of-season news conference Wednesday. "Disappointed by it. Understand that we better make some changes in terms of the things we do. We better look at every aspect of it. Schematics, personnel, approach to business. I am committed to that. I am also committed to not sitting in this position and feeling the way we feel right now moving forward."

Fichtner, a longtime quarterbacks coach for the organization, drew ire in the past two seasons for the sluggish offense. The Steelers finished last in the league with 1,351 rushing yards in 2020, down from the year before, when they finished 29th with 1,447 yards.

"We will not accept our current position in that area," Tomlin said of the run game. "We cannot. We have to attack that, and we will."

Fichtner took over for Todd Haley as the offensive coordinator beginning with the 2018 season, but he's been in Pittsburgh since 2007, when he began his tenure as the wide receivers coach in Tomlin's first year as head coach.

He's also been Ben Roethlisberger's quarterbacks coach since 2010. Their relationship appeared strained at times this season as Roethlisberger took on the expanded role of ad-libbing plays on the field when the Steelers went to an up-tempo, no-huddle offense.

The Steelers often relied on the short passing game to supplement the lack of a run game, but that led to little success in getting the ball down the field -- especially in the final six games of the season. The Steelers finished the season averaging 6.3 yards per pass attempt, which ranked 29th in the league.

But after the Week 16 win against the Colts that ended a three-game losing streak, Roethlisberger gave Fichtner credit for the second-half comeback and stuck up for his longtime coach.

"I saw that Coach Randy was taking a little bit, and he shouldn't be," Roethlisberger said last month. "He calls the play. We have to execute them. In the second half, it's not just me. He's telling me stuff in my ear. We're talking on the sideline. He should get as much if not more -- I think more -- credit than me or anyone else for that second-half performance because he's the one that's really kind of given us the insight, the direction and keeping it moving.

"To me, what I see with Coach Randy's growth is just understanding where our strengths and weaknesses are, and really, like I said, it boils down to us making plays and not the playcalling."

The Steelers have a history of internal hires for offensive coordinator vacancies. Ken Whisenhunt, Bruce Arians, Mike Mularkey and Fichtner were all promoted from position coaches, although Haley was hired after his head-coaching stint in Kansas City.

If the Steelers choose to hire in-house, quarterbacks coach Matt Canada and wide receivers coach Ike Hilliard could be in the mix for the job. Though he has just one year of NFL experience, Canada previously served as offensive coordinator at Indiana, Wisconsin, NC State, Pittsburgh, Maryland and LSU. Hilliard, meanwhile, has a decade of experience as an NFL coach, but he has served only as a wide receivers coach.

Sarrett was promoted to offensive line coach in January 2019 after a season as the assistant offensive line coach under Mike Munchak. Sarrett joined the Steelers in 2012 as an offensive assistant.

His departure is the first domino in an offseason that will likely transform the offensive line. Two starters -- left tackle Al Villanueva and guard Matt Feiler -- are unrestricted free agents, and veteran center Maurkice Pouncey could retire.

Like the offensive line, the secondary is in for some major changes, beginning with Bradley. The Steelers will likely lose versatile fill-ins Cameron Sutton and Mike Hilton in free agency and could opt to cut or restructure expensive veterans such as Joe Haden and Steve Nelson to get cap compliant.

Bradley was hired in February 2018 and coached the group for three seasons. Before that, he was the UCLA defensive coordinator and was a longtime Penn State defensive coach.