Trent Williams was carted off the field twice during the 49ers' 28-21 loss to the Seahawks at Levi's Stadium on Sunday, the second of which was due to a shoulder injury.
Coach Kyle Shanahan told reporters after the game that he was "concerned" about the nature of Williams' injury since he didn't return.
With our All Access Daily newsletter, stay in the game with the latest updates on your beloved Bay Area and California sports teams!
SIGN UP HERE Williams also was carted off the field earlier due to cramping, but returned to the game before exiting again on a cart with his shoulder injury.
The 49ers losing their All-Pro left tackle for any sort of period is not ideal, as rookie Jaylon Moore subbed in for Williams upon his exit.
Williams played in 14 of the 49ers' 16 games last season, and played every snap in the 49ers' first three games in 2021 before Sunday.
Download and follow the 49ers Talk Podcast
San Francisco 49ers
Find the latest San Francisco 49ers news, highlights, analysis and more with NBC Sports Bay Area and California.
