Hayden, who missed almost five months with a right foot injury he suffered in offseason workouts, has 21 days to be activated after coming off the physically unable to perform list.
After playing just 350 snaps last season, Hayden is hoping to reverse his struggles and aid a Raiders defense that is 11th against the pass, but 25th in interceptions (two).
Oakland liked Hayden enough in a thin 2013 draft to fall from the No. 3 pick to the No. 12 pick for just an additional second-rounder. The Raiders hope Hayden will develop into the shutdown corner they planned for over the final 11 games of the season.