Jones (foot) is active for Sunday's game against the Cardinals, Brooke Evans of the 49ers' official site reports.
Jones sustained a foot injury in the 49ers' Week 2 win over the Dolphins, but the fifth-year pro has been cleared to play in Sunday's NFC West showdown. He's logged three pass defenses and zero tackles through the first two games of the regular season while serving in a rotational role in the secondary.