The Dallas Cowboys decided one year with Monte Kiffin as defensive coordinator and Bill Callahan as play-caller was enough.
Kiffin was demoted Tuesday in favor of defensive line coach Rod Marinelli, and Scott Linehan was hired as the passing game coordinator who will call plays.
The staff shuffling -- the second in as many years -- comes after the Cowboys gave up the most yards in franchise history and finished last in the NFL in total defense and had their worst offensive output in yardage since 2005.
"If you look at staffs around this league and rosters all around this league, there's change from year to year," Garrett told The Associated Press. "And the teams that embrace the change are the ones that have the most success and again we feel like from a system standpoint, the systems on offense and the systems on defense, remain in place."
Kiffin and Marinelli came to Dallas together last year after the Cowboys fired defensive coordinator Rob Ryan and decided to switch to a four-man front with three linebackers following nearly a decade in the 3-4 defense.
Quarterback Tony Romo will have his third play-caller in as many seasons after Garrett had that role in 2012. There was even a change in the middle of this past season when Garrett reinserted himself by relaying the calls from Callahan to Romo.
"It's not really a concern at all," Garrett said. "We've had the same offensive system in place here for seven years. We feel like the transition will be really relatively smooth for everybody."
Garrett is entering the final season of his contract and is coming off three consecutive 8-8 seasons that extended the club's playoff drought to four straight years.
Garrett said Callahan will remain on staff in 2014, also the final year of his contract. He will keep his titles of offensive coordinator and offensive line coach.
"Just like you would with a player, guys are always in roles that tend to evolve and change," Garrett said. "If you have the right kind of guys on your team, they embrace those roles, understand the objective is to try to help our team first and foremost. Bill knows that."
Linehan, the former St. Louis coach who was Detroit's offensive coordinator the past five seasons, gave Garrett his first coaching job in the NFL in 2005 when he was offensive coordinator in Miami. Garrett was his quarterbacks coach that season.
"He and I have a real comfort level with each other," Garrett said. "Philosophically, we're on the same page. He has a comfort level with our system of football. The other thing he'll bring is some new blood and some freshness to it."
The Lions finished sixth or higher each of the past three years in total offense, while the Cowboys slipped to 16th, their lowest since 2002.
While improving dramatically in takeaways on defense under Kiffin, the Cowboys gave up the first two 600-yard games in franchise history and surrendered 40 first downs for the first time in league history. Their 6,645 yards allowed were almost 1,000 more than the previous club record from 2012.
Garrett said Kiffin, who will turn 74 next month, will serve more as a mentor who will "help coach coaches and coach players" after spearheading the transition to the 4-3 defense.
Marinelli was Chicago's defensive coordinator for three years under Lovie Smith before Smith was fired in 2012, when the Bears led the league in interceptions (24) and takeaways (44) and were third in points allowed.
"The success he had in Chicago as a coordinator speaks for itself," Garrett said. "To have him as a point person is exciting and to have Kiff in the overseeing role is again something we think is good for our team."
The Cowboys now have three former head coaches on the staff in Callahan, Marinelli and Linehan, who was 11-25 in two-plus seasons as coach of the Rams. He was fired after an 0-4 start in 2008 and joined the Lions a year later when Jim Schwartz was hired as head coach. Schwartz was fired last month.