49ers Defensive Line Bolstered, Offensive Line Remains Concern in Free Agency

The 49ers made key additions to their defensive front, but their offensive line depth still needs work ahead of the 2026 season.

Mar. 18, 2026 at 11:38pm by Ben Kaplan

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The San Francisco 49ers have had a mixed bag of results in free agency so far. While the team has significantly improved its defensive line by trading for Cowboys DT Osa Odighizuwa, their offensive line remains a major concern after losing starting LG Spencer Burford to the Raiders. The 49ers will likely need to address the O-line early in the draft to find a replacement for Burford, as they have not made any major free agent signings to shore up that unit. The team's ability to protect QB Trey Lance and open holes in the running game will be crucial to their Super Bowl aspirations.

Why it matters

The 49ers' defensive line was a major weakness in 2025 after Nick Bosa's season-ending injury, so the addition of Odighizuwa should provide a major boost to their pass rush when Bosa returns. However, the loss of Burford on the offensive line is concerning, as the 49ers have struggled to consistently field a strong O-line in recent years. Their ability to address this need in free agency or the draft will be pivotal to their chances of making a deep playoff run.

The details

The 49ers traded a third-round pick to the Cowboys to acquire Osa Odighizuwa, a disruptive interior pass rusher who signed a four-year, $80 million deal with Dallas just last year. Odighizuwa will join a defensive line that should be formidable when Nick Bosa and 2025 first-round pick Mykel Williams return from ACL injuries. However, the 49ers lost starting left guard Spencer Burford in free agency, as he signed with the Raiders. The 49ers have not made any major additions to replace Burford, and will likely need to use an early draft pick to find his successor.

  • The 49ers traded for Osa Odighizuwa on March 15, 2026.
  • Spencer Burford signed with the Raiders on March 14, 2026.

The players

Osa Odighizuwa

A defensive tackle acquired by the 49ers in a trade with the Cowboys. Odighizuwa is considered one of the most disruptive interior pass rushers in the NFL.

Nick Bosa

The 49ers' star defensive end who missed most of the 2025 season with a torn ACL.

Mykel Williams

The 49ers' 2025 first-round draft pick who also missed the 2025 season with a torn ACL.

Spencer Burford

The 49ers' starting left guard who signed with the Raiders in free agency.

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What’s next

The 49ers will likely need to use an early draft pick to find a replacement for Spencer Burford at left guard. They could also explore trade options to bolster the offensive line, such as a potential deal for Vikings edge rusher Jonathan Greenard.

The takeaway

The 49ers have made a significant investment in improving their defensive line, but their offensive line remains a major concern heading into the 2026 season. Their ability to address this need will be crucial to their Super Bowl aspirations.