Walker didn't practice Sunday due to an undisclosed injury, Brady Henderson of ESPN.com reports.
Walker has missed three straight days after participating in the Seahawks' first practice of training camp. Rookie Zach Charbonnet also has sat out back-to-back sessions with an undisclosed issue, so this is certainly a storyline worth following. Head coach Pete Carroll may provide a more concrete update following Sunday's practice, but if both running backs are forced to miss time, DeeJay Dallas, Kenny McIntosh, Bryant Koback and Wayne Taulapapa would all be candidates for increased work.