The Cardinals added Treadwell to the practice squad Wednesday, Darren Urban of the team's official site reports.
Treadwell will join up with Arizona after being let go from New England's practice squad last Tuesday. The 27-year-old recorded 33 receptions (on 51 targets) for 434 yards and a touchdown over 12 games with Jacksonville last season, and he could be a reliable game-day elevation for the Cardinals' under-manned wide receiver corps.