Over the past two seasons, the Cardinals have spent two first-round picks and over $100 million on a defensive line that has struggled anyway.

Arizona has the worst Pro Football Focus tackling grade in the league this season, as its defense has taken a step back in Year 3 of Gannon's stay.

The Cardinals have been a bottom half defense this season. Last week's film study shows why it might be difficult to fix that unit in one offseason.

Two were on the field for all of the defensive snaps — cornerback Will Johnson and Mike linebacker Cody Simon. Safety Dadrion Taylor-Demerson missed two and cornerback Denzel Burke seven, while safety Budda Baker and inside linebacker Akeem Davis-Gaither each missed nine.

First off, the team activated L.J. Collier from the IR, and they will have another defensive lineman in the rotation. They also signed quarterback Logan Woodside, the former Cincinnati Bengals practice squad quarterback, who has spent most of this season on the Steelers practice squad.

Arizona Cardinals head coach Jonathan Gannon blamed some of the NFL rules for the lack of tackling from the Cardinals this season.

At 23 years old, he has 5,376 career scrimmage yards, surpassing Clinton Portis (5,327) for the third-most yards by a player under the age of 24 in NFL history. Only Christian McCaffrey (5,443) and Pro Football Hall of Famer Barry Sanders (5,391) have more. Both are well within reach.

This December 21 clash features two of the worst defenses in the NFL. Our Falcons vs. Cardinals predictions anticipate a high-scoring affair in Week 16.

Christmas brings playoff gifts for multiple teams as Week 17 gets ready begin. Here are USA TODAY Sports' playoff predictions.