Oakland has now added six free agents, and all of them are on the defensive side of the ball (three linebackers and three defensive linemen).
Walker is considered a rotational player more than a starter, but he could get a chance to start. He is solid against the run and he is a versatile player overall.
Meanwhile, the NFL Network has reported Oakland has interest in Tampa Bay tight end Kellen Winslow. Winslow, who’ll turn 30 in the summer, played just a few snaps in 2012. He is recovering from a knee injury. In the past, he has been a productive player, but his injury history is a concern. The Raiders have a hole at tight end with the departure of Brandon Myers -- who had 79 catches last season -- to the Giants.