Kyle Shanahan, the head coach of the San Francisco 49ers, has built a reputation for making bold and unconventional decisions rather than settling for safe options. This offseason, when the team needed experienced leadership on the defensive side of the ball, Shanahan chose not to simply fill the gap with a routine hire. Instead, he pursued a veteran coach with extensive NFL experience and a background in rebuilding struggling defenses.
To strengthen the defensive coaching staff, the 49ers have brought in Matt Eberflus as the assistant head coach of defense. The role was previously held by Gus Bradley during the previous season. Eberflus joins the staff after a challenging stint with the Dallas Cowboys, where he served as defensive coordinator.
Eberflus brings more than 20 years of NFL coaching experience. From 2018 to 2021, he led the defense for the Indianapolis Colts, building a strong reputation for his defensive systems. His success in Indianapolis eventually led to him becoming the head coach of the Chicago Bears. However, his tenure in Chicago ended midway through the 2024 season.
After leaving Chicago, Eberflus joined Dallas in 2025 with the responsibility of improving a defense that had struggled for several years. Despite the expectations, the results were disappointing. Under his leadership, the Cowboys’ defense ranked 30th in the league in total yards allowed, giving up an average of 377 yards per game. They also finished last in the NFL in points allowed, surrendering 30.1 points per game during the 2025 season.
The defensive struggles had a major impact on the team’s overall performance. Even though the Cowboys experienced one of the strongest offensive seasons in their franchise history, the defensive issues undermined their ability to win consistently.
Eberflus also faced significant challenges before the season even began. Just one week before the opening game, the Cowboys traded star pass rusher Micah Parsons to the Green Bay Packers, removing the defense’s most dominant player. Losing such a key talent made the task of rebuilding the defense far more difficult.
Further complications emerged within the roster itself. Cornerback Trevon Diggs reportedly clashed with Eberflus over defensive strategies, particularly regarding the use of zone coverage versus man-to-man schemes. The disagreement eventually escalated, and Diggs was ultimately released from the team.
Throughout the season, Eberflus remained under heavy scrutiny as the defense continued to struggle. When he was eventually dismissed from his position, he accepted full responsibility for the outcome. He openly acknowledged that the defense had failed to show the consistent improvement that the organization expected and admitted that the team’s progress had been uneven rather than steadily improving.
Despite the disappointing results in Dallas, Shanahan saw value in Eberflus’ experience and decided to bring him to San Francisco. The decision also came at a time when the 49ers were dealing with significant changes within their defensive coaching staff.
The shift began when former 49ers defensive coordinator Robert Saleh accepted the head coaching job with the Tennessee Titans. Saleh’s departure created a major vacancy within the San Francisco coaching structure.
Soon after, Gus Bradley—who had served as the 49ers’ assistant head coach of defense—left the organization to join Saleh in Tennessee as the Titans’ defensive coordinator. Bradley and Saleh share a long professional history that dates back to their time working together with the Seattle Seahawks under head coach Pete Carroll during the early 2010s.
When Saleh secured another opportunity as a head coach, it was widely expected that Bradley might follow him. The connection between the two coaches has remained strong for years. Saleh also brought along another former 49ers assistant, Greg Scruggs, who previously worked as San Francisco’s assistant defensive line coach.
These departures left Shanahan needing to fill two important leadership positions on the defensive side of his coaching staff during the same offseason. To address the defensive coordinator vacancy, he hired Raheem Morris as the team’s new defensive coordinator. Morris became the 49ers’ fifth defensive coordinator in five years, highlighting the constant changes within the role.
Morris brings significant credentials to the position, having previously coordinated the defense of the Los Angeles Rams during their championship run in Super Bowl LVI. His experience with a title-winning defense made him an appealing choice to lead San Francisco’s unit.
With Morris handling the coordinator role and Eberflus stepping in as assistant head coach of defense, the 49ers are attempting to rebuild stability and leadership within their defensive coaching structure. Eberflus now receives another opportunity to prove his abilities after his difficult year in Dallas, while Morris also seeks to reestablish himself following his previous role as head coach of the Atlanta Falcons.
Although the 49ers are still finalizing the structure of their defensive staff ahead of the 2026 season, the organization believes the combination of experienced coaches can help stabilize the unit. With Shanahan continuing to guide the overall direction of the team, the franchise hopes these moves will provide the foundation needed to rebuild and strengthen the defense moving forward.