Simon (knee) is active for Sunday's game against Atlanta, Darren Urban of the Cardinals' official site reports.
Simon made an early exit from last Sunday's loss to the Texans due to a knee injury. He was able to log a trio of limited practices this week and has been cleared to take the field Sunday. The rookie linebacker logged every defensive snap for Arizona from Week 10 to Week 14 and will likely take on a major role again versus the Falcons.