The Seahawks announced the news, adding they released Terrence Magee to make room on the roster.
Ian Rapoport of NFL Network explained the reasoning:
As Rapoport previously reported, the 29-year-old running back worked out for the New York Jets on Tuesday, but instead, he will join a team that suddenly needs depth at running back. According to Bob Condotta of the Seattle Times, starter Thomas Rawls will miss an extended period of time with a cracked bone in his fibula.
According to NFL reporter Rand Getlin, eight teams expressed interest in Spiller, several of which he could have signed with last week.
Spiller will join C.J. Prosise on the depth chart behind Christine Michael, who will remain the go-to option in the backfield.
A top-10 pick in 2010, Spiller was once one of the most dynamic running backs in the NFL, making the Pro Bowl in 2012 with the Buffalo Bills after totaling 1,703 yards from scrimmage. He averaged 6.0 yards per carry and 10.7 yards per reception that season while splitting playing time with Fred Jackson.
Unfortunately, he wasn't able to replicate that success in 2013, totaling just 933 rushing yards and two total touchdowns.
Injuries have taken a toll on the running back since then, limiting him to just nine games in 2014 and 13 games last year, his first season with the Saints. When he was healthy, he struggled to see the field and ended up with just 351 yards from scrimmage on 70 total touches in 2015.
New Orleans head coach Sean Payton was encouraged by what he saw from the running back during the offseason.
"C.J.'s health and his movement skills look noticeably different," Payton said in May, per Katherine Terrell of the Times-Picayune. "He worked his butt off in the offseason to get the strength back in that leg he had his injury. That's been real encouraging."
But he couldn't overtake Mark Ingram, Tim Hightower or Travaris Cadet on the depth chart once the season began, making him expendable. The veteran then became a healthy scratch in Week 1 and was released soon after.
Spiller will now get a chance at a fresh start with the Seahawks, hoping the team will find a way to use his versatility out of the backfield. It's a low-risk acquisition for the squad at this stage, with the potential for a high reward if the running back rediscovers some of the magic that made him a fantasy football star.