Walker departed Sunday's game at the Rams due to an ankle injury.
After a Seahawks possession in the second quarter, Walker was seen getting examined by team personnel and later remained on the sideline with his right leg propped up on the bench. It's unclear if he has a chance to return, but as long as the rookie second-round pick is out, this backfield will be the domain of DeeJay Dallas and perhaps Tony Jones, with Travis Homer (illness) inactive and Rashaad Penny (ankle/fibula) out for the season.