Tommy Kelly was injured in the third quarter against Tennessee on Sunday, one play before Titans' running back Chris Henry scored on a 24-yard touchdown run in the direction where Kelly would have been.
Oakland's leader in tackles among defensive linemen, Kelly lay on the turf before being helping being off the field. He did not return and wore a brace on his right knee in the locker room afterward.
The Raiders can hardly afford to lose Kelly, who is their most versatile defensive lineman. Though he starts at right defensive end, he routinely plays at the under-tackle spot as well as at nose tackle.
With defensive tackle Gerard Warren having missed the last three games with a thigh injury, Oakland is already short-handed up front. One option the team will consider if Kelly cannot play is promoting defensive tackle Josh Shaw from the practice squad.