The Seahawks made the roster moves Saturday before Sunday's game against Tennessee.
Walters saw action in four games for the San Diego Chargers in 2011 with two catches for 27 yards. He signed with Minnesota in April 2012 but was released during training camp. The Seahawks signed him to their practice squad last December.
Spitz signed with Seattle on Sept. 25. He did not play in the two games he was with the team.