The Cardinals activated Nolen (calf) from injured reserve, and he is active for Monday's game against the Cowboys, Darren Urban of the Cardinals' official site reports.
The rookie first-rounder has been cleared to make his NFL regular-season debut after missing the first seven games due to a calf injury he sustained during training camp. Nolen will likely work in a rotational role at defensive tackle when Calais Campbell and Dalvin Tomlinson are resting.