The Monday after the San Francisco 49ers walloped the Arizona Cardinals in Week 11, head coach Kyle Shanahan confirmed to reporters linebacker Tatum Bethune suffered a high-ankle sprain in the victory and would miss some time, perhaps a couple of weeks at least.
On the positive side, the second-year pro who has admirably filled in for the injured Fred Warner isn't likely to land on injured reserve.
Yet Bethune's injury will have a ripple effect that'll impact the Niners defense in more ways than one.
For starters, Bethune has been an above-average run defender, the kind of player San Francisco has sorely needed in recent years to shore up an otherwise shoddy ground defense. He's had at least 10 tackles per game since taking over in Warner's stead, and that kind of production now has to fall upon the shoulders of someone else.
According to Shanahan, the primary go-to with Bethune out will be veteran Curtis Robinson.
"Curtis has been preparing for that opportunity for a while," Shanahan said after announcing the Bethune news.
Robinson, a perennial practice squad body and sometimes call-up, has veteran savvy and experience, but there's a clear drop in talent.
And that's just one area of concern.
49ers will sorely miss Tatum Bethune's presence over next 2 weeks
Robinson did flash some excitement in the 2024 preseason before an ACL tear and looked solid enough last August in exhibition matches, too. Like Warner and Bethune thereafter, Robinson has experience as the defensive play caller, so getting the green dot on his helmet won't be anything new to him.
That said, and as Bethune found out after the Warner injury, there's an adjustment period when taking on defensive captaincy duties, and it'll be challenging for Robinson to acclimate to that new role on such short notice.
Beyond that, though, the 49ers are simply running out of plausible options at linebacker to beef up the depth chart behind Robinson, Dee Winters, Luke Gifford and the controversial third-round rookie, Nick Martin, who only recently has worked his way out of the weekly inactive list.
The Niners simply can't afford more injury attrition here if they hope their second level of defense can maintain some sort of prowess.
Fortunately, there are only two more games before San Francisco has its bye in Week 14, meaning Bethune likely only misses the two contest before a (hopeful) return to action in Week 15 against the Tennessee Titans.
Fully healed, one can hope.