Thomas Rawls will miss the remainder of the season with a broken ankle and torn ligaments.
"I think the torn ligaments are really the problem," Pete Carroll said. "I don't think he's going to have to have an operation, from what I understand."
Rawls suffered the injury in the first quarter.
Rawls' season ends with 830 yards on 147 rushes.
The Seattle Seahawks hope Marshawn Lynch will be able to return from his sports hernia injury.
"We'll see how Marshawn does," Carroll said. "He was back in rehabbing with us. We'll see where he is. He's got a chance to get back.
"It's all about getting back in shape and getting right. I don't know what that timetable is at this point. Our trainers can't tell yet. That'll be the next thing we look forward to and see how that works. And in the meantime, we'll figure it out."