49ers-Cardinals preview: What the heck happened to Arizona’s defense

The San Francisco 49ers and Arizona Cardinals square off for their second time this season, with the 49ers looking to avenge an 18-15 overtime road loss. The 49ers had the game in hand, but a late defensive collapse cost them.

The Cardinals offense has a lot of problems, due to injury, but the defense has had plenty of its own problems. They have had one of the better units in the league for the past few years, but they have fallen on hard times this season.

Injuries, scheme, and other issues all have led to various problems. We chatted with Revenge of the Birds site manager Seth Cox this week, and he offered some helpful insight into what has happened to the once vaunted Cardinals defense.

They bet on a combination of young players growing and old players bridging the gap. For the most part that has not happened. Outside of Antoine Bethea, no veteran has played extremely well. If we are calling Tyvon Branch a veteran then he has. Meanwhile, Karlos Dansby has been okay, Tyrann Mathieu is not the same playmaker he once was and the defensive line is a bunch of guys who play the run well, but can't rush the passer.

The Cardinals have two players that other teams would covet on defense at this point: Chandler Jones and Patrick Peterson. The sad part is, those are two of the most difficult positions to fill in football and the Cardinals have, and yet this is the defense.

The young guys, meanwhile, have been yo-yo'd in and out of the lineup while also being asked to learn and play multiple positions. Haason Reddick was flashing at the inside linebacker spot, Deone Bucannon comes back from injury and now Reddick is asked to learn to play outside linebacker. Budda Baker is playing the Tyrann Mathieu, Tyvon Branch and also slot cornerback role when he is on the field, which is not often, plus is being used a punt gunner.

Oh and did I mention Robert Nkemdiche? No, well that's because he's played 69 snaps on the season, in three games (game two, game three and game seven). He has been battling a calf issue and then when he got on the field, he inevitably goes offsides, then the Cardinals pull him and he doesn't get any consistent playing time.

Then there is, what could be the bigger problem, and that is defensive coordinator James Bettcher.

He took over a good defense and did well with it, but as the team has turned over the roster this year, it has completely bottomed out. Bettcher's defenses had DVOA rankings of third in 2015 and 2016, but are currently 20th in 2017. Maybe he was dealt a bad hand, maybe they have struggled to identify talent, maybe it is the way they are using talent, or maybe it is a big mix of all of that, but the reality is they have one of the worst scoring defenses in the NFL and have only played two good games all year. That was against the hapless Colts and the Brian Hoyer-led 49ers.

Against average to good offenses the Cardinals have allowed: 35 points to the Lions, 28 points to the Cowboys, 34 points to the Eagles, 33 points to the Bucs and 33 points to the Rams. That's 32.6 points per game. They are 1-4 in those games.

Can they fix it? If you would have asked me at the beginning of the year I would have said yes. Now, I honestly don't know.