Through four games of his NFL career, it's clear Detroit Lions rookie cornerback Terrion Arnold has work to do. Penalties have been a clear problem, particularly pass interference, as he adjusts to how the NFL officiates pass defense. His Pro Football Focus grades have been rather dismal.
If there was a good alternative, it might make sense to reduce Arnold's snaps or even take him out of the starting lineup. But there is not, and it's clear the Lions' coaching staff is going to give the team's first-round pick this year plenty of leeway to grow and improve. The bye week was probably helpful on that front.
It has also not all been bad for Arnold. When matched up against Marvin Harrison Jr. in Week 3, he allowed just two catches on six targets (according to PFF) to the Cardinals' highly-touted rookie receiver.
Analyst gives Terrion Arnold an unfairly terrible early grade
Ian Valentino of the The 33rd Team recently graded all 32 2024 first-round rookies at the quarter-point of the season (through Week 4).
Valentino gave Arnold a D-.
"While Terrion Arnold's ability to play cornerback and safety was a selling point for teams, his athleticism is best served at either nickel corner or safety."
"Detroit has instead put him at right cornerback more than in the slot, and Arnold is struggling. He's allowed 64 percent of targets to be completed for 178 yards and one touchdown while committing eight penalties."
Arnold has allowed 64 percent of passes in his direction to be completed so far this season (16 of 25, per PFF). Those 25 targets are second-most among rookie cornerbacks, and Arnold has played one less game than Buccaneers' cornerback Tykee Smith (32 targets against).
In the league overall, 18 cornerbacks have been targeted at least 25 times so far this season. Arnold's 64 percent completion rate allowed is in the bottom half (i.e. ranked highest to lowest, with lower being good) of that group.
Since Week 1, when he allowed eight catches on 10 targets in his coverage, Arnold has allowed eight catches on 15 targets (53.3 percent catch rate allowed) and 41 of the 121 yards he allowed from Week 2-4 came on one play. Per PFF, he has allowed passer ratings of 51.4 and 56.3 in the last two games.
The penalties are a well-deserved headline and concern from Arnold's first four games. Valentino's grade is aggressively unfair though, and it's bordering on ridiculous if you dig into the most recent numbers beyond penalties.