Last week, the 49ers suffered the loss of their best defensive player for the remainder of the season when Fred Warner‘s ankle was fractured and dislocated. The team officially placed him on injured reserve yesterday while, at the same time, hosting five free agent linebackers for workouts. Per Howard Balzer of CardsWire, linebackers Ben Niemann, Jalen Reeves-Maybin, Chandler Wooten, and two others were in San Francisco for the tryout yesterday. 
One of the worst parts about losing a player as talented and reliable as Warner is that, considering he’s missed one of a possible 122 regular season games in his career, there usually isn’t much incentive to stack talent at the position behind him. The 49ers typically run two off-ball linebackers in their base defense. The starters are Warner and Dee Winters, and before last week’s game, there had only been five defensive snaps all season in which both were not on the field.
It was Tatum Bethune that subbed in for Warner in the remainder of last week’s game. Bethune was a seventh-round draft pick out of Florida State last year who played almost exclusively on special teams as a rookie. Appearing in 11 games, he saw defensive snaps in just five. He only saw more than four snaps in one game — the 6-11 team’s regular season finale in which Bethune was given a chance to start. The Week 18 start was not a sign of things to come, though. When Bethune entered for Warner last week, he was seeing his first defensive snaps since the three he played in Week 1 of this year.
So, while the 49ers may be comfortable moving forward with Bethune as the starting middle linebacker based on his familiarity with the defense over the past year and a half, one can hardly blame them for trying out some potential help. Niemann is the most experienced of the crowd. Starting his seven-year career in Kansas City, Niemann has been a dependable rotation defender for the Chiefs, Cardinals, and Lions over his career. He’s played in 103 total games, starting 25, and aside from his rookie season and a down year in Denver in 2023, Niemann’s averaged just over 50 tackles per season.
Reeves-Maybin is the next most experienced linebacker. Though he spent many years (seven in Detroit, one in Houston) as a depth piece and special teamer, Reeves-Maybin has shown he can perform as an injury replacement with 14 spot starts for the Lions, including 11 in 2021. He and Niemann were actually on the same defense in Detroit last year. Wooten was a depth piece and special teamer for the Panthers the last few years, earning two starts last year. He had signed briefly to San Francisco’s practice squad last year, returning to Carolina after a week.
The other two linebackers attending the workout were undrafted rookies Stone Blanton and Kam Arnold. Blanton signed with San Francisco out of Mississippi State, spending the offseason with the 49ers before failing to make the initial 53-man roster. Arnold, coming out of Boston College, followed a similar path with the Commanders. No contracts came immediately from yesterday’s workouts, but it will certainly be something to keep an eye on, depending on how Bethune performs in place of Warner as the season goes on.