The San Francisco 49ers' worst fears were confirmed on Friday, as head coach Kyle Shanahan informed reporters that linebacker Curtis Robinson, who was carted off during Thursday's practice, suffered an ACL injury, effectively ending his season.
While Robinson hasn't been a significant contributor on defense this season, he has been a key presence on special teams, participating in 78 percent of the unit's snaps, according to Pro Football Reference.
The 49ers will likely turn to their practice squad and could elevate DaShaun White to shore up their linebacker group ahead of Sunday's game against the New England Patriots.
Now in his fourth season with the 49ers, Robinson entered the NFL as an undrafted free agent with the Denver Broncos in 2021.