Detroit Lions Week 1 rookie review: 4 start vs. 49ers

Week 1 of the 2021 regular season is in the books for the Detroit Lions and seven of the team’s 10 rookies made their NFL debuts. The three rookies that were inactive were second-round pick DT Levi Onwuzurike who was dealing with a hip injury, seventh-round RB Justin Jefferson, and recently signed UDFA OL Tommy Kraemer.

Let’s take a closer look at the seven rookies who were active against the San Francisco 49ers.

Penei Sewell, LT

With starter Taylor Decker landing on injured reserve, Sewell made the switch from right to left tackle, and as noted by the Lions' PR department: at 20 years and 338 days old, “Sewell (became) the youngest player in NFL history to start a game at LT and the second-youngest Lion to appear in a game (since 1950).”

Coach Dan Campbell+ said the concept behind moving Sewell to the left side was prompted by their opponent, lining the rookie up across from Nick Bosa.

“He’s powerful, he’s big, he’s explosive,” Campbell said of Sewell. “I mean, that’s what he had done (in college) and I know he embraced it. Like, he was really excited to go back to left. So, it just felt like the right move, and from that standpoint, we felt like he performed pretty well.”

Pretty well may have been an understatement. On 92 (!) snaps, Sewell earned a 75.6 grade from PFF (third-highest on the Lions offense) and Bosa only got two hits on the quarterback when squaring off in their one-on-ones.

“He’s going to be good,” Bosa after the game. “He’s more comfortable on the left, and I could tell from the tape I saw of him on the right. I told him after the game he’s better on the left.”

If Sewell strings together a few more above-average games, it’s fair to speculate if he will stay at left tackle once Decker is healthy. Campbell’s not ready to start thinking about that just yet.

“I’d love to entertain that, but we’re so far away from that right now,” Campbell said at his Monday press conference. “We’re just - how do we put the best lineup out there for Green Bay right now? We’ll worry about that when Decker comes back, but right now, I know that we feel good with Sewell being at left. We asked him to move over there and he accepted the challenge, did well, and we’re going to need another good performance out of him.”

Alim McNeill, NT

McNeill got the start at nose tackle, as he has all offseason, and he saw 28 snaps (51 percent of defensive snaps) during the game. That’s a pretty hefty chunk of playing time for the nose tackle role in this scheme, but the 49ers are an aggressive running team, so McNeill was likely out there to counter their approach. Next week against the Packers, it wouldn't be surprising if those numbers were scaled back some.

Ifeatu Melifonwu, CB

Melifonwu appeared to be playing some matchup football at the beginning of this contest but he was forced into the starting lineup when Jeff Okudah was injured and left the game. An injury we later found out was an Achilles rupture and that he would be lost for the season as a result. The Lions do plan on bringing in more cornerback depth, but in the interim, Melifonwu looks like the most likely candidate to take over the vacated starting role.

“Look, he’s been working hard, and he quietly has really improved,” Campbell said of Melifonwu. “He’s another guy from spring that has just quietly had a good spring and a good camp. So, yeah, he’s probably—there’s a good chance he’s the next guy up, but look, we’ve got two other young guys, too, in Bobby Price and (Jerry) Jacobs. So, we’re going to put the best combination out there and see where we go.”

Amon-Ra St. Brown, WR

St. Brown was the Lions' starting slot receiver and (after Tyrell Williams exited with a concussion) finished the game with the second most wide receiver snaps on the offense. Despite the extra opportunities, St. Brown only saw four targets and he was only able to turn that into two receptions for 23 yards.

T.J. Hockenson, D’Andre Swift, and Jamaal Williams figured to be the primary targets in this scheme—and they were, each had eight receptions—but St. Brown was believed to be in the mix as well—he just wasn’t able to separate himself from the rest of the Lions’ skill players in this game.

Regardless of whether Williams misses any games or not, St. Brown needs to show some more of that swagger he showed off all training camp.

Derrick Barnes, LB

It's clear coaches are still building trust with Barnes, as he only saw five defensive snaps all game, but his run defense showed up late in a big way and it left many wondering when he will start getting opportunities earlier in the game.

The biggest obstacle facing Barnes—other than lack of experience—is the linebacker rotation. Currently, Alex Anzalone is wearing the green dot helmet and he played every defensive snap in the contest. That means Barnes would have to take snaps away from Jamie Collins, the other starting linebacker, but he was equally as stout against the run and plenty more experienced.

This may be a slow process.

AJ Parker, NB

As expected, Parker was the Lions' starting nickel corner, but because of the 49ers' run-oriented offense, that meant Parker’s opportunities would be fewer than normal—he only saw 21 snaps, 38 percent of defensive snaps. Despite the small workload, Parker still showed up big as he had all preseason, especially in run support.

Next week in Green Bay, look for Parker to get more time on the field, and if he continues to play as well as he has been, he could turn into a real weapon for defensive coordinator Aaron Glenn.

Jerry Jacobs, CB

While Campbell said Jacobs will be in the mix to challenge for Okudah’s starting role, it’s worth noting that he didn’t play a single defensive snap in Week 1. Jacobs did play key roles on special teams, and figures to continue that role moving forward, but how much more can he contribute at this stage of his development? The Lions may need to find out as quickly as possible.