Detroit Lions' defense may have an unfixed Achilles' heel

After having one of the worst pass defenses in the NFL last season, the Detroit Lions overhauled their cornerback depth chart this offseason. Carlton Davis, Amik Robertson and two rookies (Terrion Arnold and Ennis Rakestraw) are all arguably better than any cornerback they had on the roster last season.

After a lack pass rushing depth last year, that situation is looking better-even if adding a veteran edge rusher could still be on the radar. And the Lions' linebacking corps looks deep and very good, just a few years after looking pretty ugly.

As expected, the Lions were among the worst teams in the league last year allowing production to wide receivers, especially outside receivers. If the aforementioned offseason additions at cornerback don't fix that, it'll be a huge problem. If the pieces of what should be a very improved defense don't come together well, one obvious person will be feeling heat.

Does the Lions' defense have an unfixed, exploitable flaw?

Maurice Mouton of Bleacher Report drilled down to one roster flaw that could derail the 2024 season for each top Super Bowl contender. For the Lions, it might be one that's easy to overlook.

Intermediate pass coverage, and Mouton put the spotlight on the Lions' linebackers.

Linebacker Jack Campbell, a 2023 first-rounder, allowed a 128.2 passer rating, an 80.6 percent completion rate and two touchdowns in coverage last season.
"The Lions' veteran linebackers didn't make much of an impact on passing downs, either. Alex Anzalone allowed a 97.2 passer rating and two touchdowns in coverage, while Derrick Barnes didn't log a single pass breakup."
"Don't be surprised if offensive coordinators attack the Lions defense with tight ends and slot receivers to expose their coverage liabilities in the middle of the field."

For what it's worth, Anzalone's Pro Football Focus coverage grade (66.1) was top-35 among qualifying linebackers last year. He was also targeted in coverage 74 times during the regular season (per PFF), and PFF marked him for zero touchdowns allowed in his coverage during the regular season (one in the playoffs).

Campbell did really struggle in coverage last year in coverage, with a 35.3 PFF coverage grade (76th out of 77 qualified linebackers) to back up the numbers Mouton cited.

On 374 coverage snaps last season, PFF gave Barnes zero pass breakups as he allowed 32 catches on 40 targets and a 97.6 passer rating in coverage.

The Lions' linebackers, Campbell and Barnes in particular, were not exploited in coverage as much as they could have been last year because there were bigger profits elsewhere in the passing game for opposing offenses to take. With that area fixed, opposing offensive coordinators will have to look for different matchups to exploit. In a broad sense, isolating Detroit's linebackers in coverage against tight ends and running backs looks like a path to success.