After a 10-3 victory over the Chicago Bears, a smiling Aaron Rodgers remarked post-game, “We have a defense.”

In the first three weeks of the season, the Packers wouldn’t give up more than 16 points. Then, things started to fall apart.

Via Sheil Kapadia of The Athletic: “In the past six weeks, the Packers’ defense ranks 31st in yards per play allowed, 30th in net yards per pass play, 30th in big completions, 23rd in points per game, 24th in sack percentage and 26th on third down. The focus in Green Bay is always on Rodgers, but that defense needs to play a lot better if they want to be taken seriously as Super Bowl contenders.”

Some of the struggles are a function of playing better offenses (or opposing offensive coordinators discovering the Packers’ weaknesses). Even so, the slide has been dramatic.

With 11 moving parts, the issues are diverse, but one player who needs to improve for the betterment of the entire unit is inside linebacker Blake Martinez.

Martinez is entering the final year of his rookie contract, and if The Athletic report last year is true, Martinez “views himself among the best inside linebackers in the league and will seek to be compensated accordingly.”

If Martinez continues to play like he did Sunday, not only will he not receive a contract commensurate with the salary band of his inside linebacking peers, but he might also be looking for work outside of Green Bay.

Here’s what I wrote in my takeaways from Sunday regarding Martinez’ play: “Inside linebacker Blake Martinez also had another rough game. Yes, he led the team in tackles (12 total, five solo), but his limitations were on full display: he’s an undersized inside linebacker with passive run-stopping instincts and less-than-ideal speed in space.”

Long-time Packers beat reporter Bob McGinn, now writing his grades for The Athletic, noted something similar: “(Martinez) gets people down, but not where a good defense needs them down…In coverage, his play is equally ineffectual. He drifts, he’s a limited athlete and he’s slow. Maybe the coaches think command of the defense makes him untouchable. If not, Goodson, Burks and rookie Ty Summers all are available.”

Formerly an allusive quality in Green Bay, Martinez is reliably healthy. Pettine also trusts him to quarterback the defense.

Even so, it’s the aforementioned shortcomings that are lowering the floor on this defense.

The most egregious example from Sunday comes late in the fourth quarter with the Packers needing a stop. Down by multiple scores knowing the Chargers are in a kill-the-clock situation, Martinez and the Packers could reasonably gamble on the play being a run. Yet, on 2nd-and-3, Melvin Gordon takes the ball seven yards to create a new set of down.

As the hole opens to the left, Martinez plays passive, He waits too long, and by the time he has a one-on-one tackle opportunity with Gordon, he gets run over. Linebackers have to be better in these situations, especially when they’re playing without linemen in their face.

Perhaps it would be more excusable if he stops the runners in their tracks upon contact, but he’s not doing that. In the above clip, the Packers have Oren Burks in alongside Martinez. Burks, perhaps on a run blitz, occupies the interior offensive lineman. Martinez bounces on his heels before committing. He grabs at air, but it’s Za’Darius Smith who makes the eventual stop.

Mike Pettine has employed what ostensibly looks like a 5-1 alignment, with five defenders across the line of scrimmage and Martinez as the lone true ‘backer. The goal is to keep blockers off Martinez, but it’s not making a substantive difference. In the example below, the frontside guard pulls outside. He’s not making the quick read and getting out in front. As a result, he gets caught in the wash and Austin Ekeler takes it for a big gain.

It’s not much better in the passing game either. As mentioned earlier, Martinez has struggled in space. He collects tackles, but a tackle at the contact point counts the same as a whiff-and-recover seven yards down the field.

The simple fact is that Martinez might just be a guy. Standing at just 6-2 and 230-ish pounds, Martinez doesn’t have great size to hold the point and shed against linemen consistently. Additionally, he doesn’t have the closing speed, so he takes broader angles, opening up bigger cutback lanes.

New contract or not, the Packers still need to see improvement from No. 50. And it’s also not all his fault, either. Kenny Clark hasn’t played particularly well lately. Against the Chargers, he struggled to hold the point of attack and was blown off the ball a few times. They also executed double teams with too much ease.

Also, as mentioned above, Pettine likes to employ single-linebacker alignments, but he might have to dedicate heavier boxes (read: more true linebackers).

Regardless of what the analytics say about stopping the run, the Packers lost the time of possession battle and, eventually, the game in part because the defense couldn’t stop the run.

Each team has an Achilles heel; it’s only a matter until that flaw becomes fatal. Unless these issues get patched, it’s likely going to be the source of a playoff exit.