The Cardinals activated defensive end J.J. Watt off injured reserve on Monday night ahead of Arizona's matchup against the Rams in the wild-card round.
Watt, 32, returned to Arizona practice last week as he completed rehab from a torn labrum, bicep, rotator cuff and separated shoulder. Watt underwent surgery in late October, but he is already back on the field as Arizona seeks a playoff win over its NFC West rival.
Watt teased his return on Monday morning in a video released on his Twitter account.
Arizona will be adding a major piece to its front seven if Watt is even remotely healthy on Monday night.