The Seahawks believe running back Fred Jackson suffered a high ankle sprain, John Boyle of the team's official site reports.
The diagnosis hasn't been confirmed, but if it is indeed a high ankle sprain, Jackson will likely be out for at least a week or two. He was having a nice game as the passing-down back against the Lions on Monday, gaining 54 yards on just five touches (two catches) in Marshawn Lynch's (hamstring) absence. Thomas Rawls is now the only healthy running back on Seattle's roster.