Walker is expected to be a top jersey seller despite Rashaad Penny and Chris Carson returning to Seattle's backfield.
Ken Walker III, who joins a run-first offence, was named to the NFLPA's Rising Stars list.
The rankings include on-field performance, NFLPA partner demand for content and promotion,
Curt Warner, Shaun Alexander, and Marshawn Lynch were popular Seahawks backfielders.
Alexander receiving NFL MVP in 2005 and Lynch becoming a fan favourite for his punishing rushing style and helping the club win the Super Bowl in 2013.