Film Review: Trent McDuffie in the slot unlocks Steve Spagnuolo’s playbook

Ever since Steve Spagnuolo became the Kansas City Chiefs’ defensive coordinator in 2019, his unit’s slot cornerback has been a critical part of his scheme.

Halfway through Spagnuolo’s first season, safety Tyrann Mathieu took over the role. Playing there unlocked Mathieu’s ball skills and football IQ — and he became one of the catalysts for the defense’s dramatic late-season improvement.

But halfway through the 2020 season, the Chiefs moved rookie cornerback L’Jarius Sneed into the role — and ever since, he has been exceptional in it. While Sneed didn’t have the coverage ability that Mathieu had brought to the position in 2019, his skills against the run — and in blitzing — helped the Chiefs fit the run from their nickel personnel packages.

Still, Sneed wasn’t the best cover corner from the slot. While he has good length and terrific long speed, Sneed doesn’t have the quick feet (or fluid hips) usually required for slot corners. With everything else he provided, it wasn’t a huge problem; the Chiefs simply didn’t ask Sneed to do much beyond carrying a route vertically or sitting in a zone window.

But Sneed’s use in the slot created another problem. With his combination of physicality, long speed and terrific ball skills, Sneed is also the team’s best outside corner. When he is primarily in the slot, he cannot cover elite wide receivers — such as the Cincinnati Bengals’ Tee Higgins and Ja’Marr Chase — on the outside.

So over the past two weeks, Spagnuolo has sought to solve this problem by having Sneed shadow the other team’s best receiver. While he hasn’t necessarily shut these players down, Sneed has been playing well; the plays he’s given up have been tough catches.

With Sneed no longer in the slot, his former role has fallen to rookie cornerback Trent McDuffie. While he was primarily acquired to play outside, McDuffie’s been terrific in the slot.

Let’s take a look.

Blitzing ability

Whether it’s on early down rollouts or obvious passing situations, Spagnuolo loves to send his slot players on blitzes — and McDuffie has proven to be quite capable. He had his first career sack during Sunday’s 27-24 win over the Denver Broncos.

We see that McDuffie is coming through the B-gap — but with defensive tackle Chris Jones also there, McDuffie has to take a wider angle on his blitz upfield. But he still has enough flexibility to turn a tight corner and chase Wilson down. With the Broncos almost certain to score, his strip ends the drive.

Tackling and ability to fit run

One of Sneed’s best attributes in the slot is his tackling ability and fitting the run. This helps the Chiefs to defend 12 personnel from the nickel when needed. With Sneed on the outside, he’s not as involved in the run fit — but McDuffie’s also been capable.

McDuffie doesn’t have the length/size to form-tackle, but he’s still been capable. While McDuffie tends to tackle lower, he times his dive at the ball carrier’s legs well — and has enough strength to slow the ball carrier. He’s also made multiple stops short of the sticks on catches, which shows his downhill explosiveness — and the strength to get critical stops.

Man coverage ability

As great as Sneed has been from the slot, one of his main issues was covering wide receivers who have a two-way go against him — meaning they could run a route on either shoulder. Sneed’s a bigger physical cornerback who struggles to cover a lot of ground — which is typical for a player with his physical profile.

McDuffie, however, doesn’t have that same issue. A fluid athlete with great click-and-close — the ability to close on a route and explode on the ball — McDuffie typically plays with hard inside leverage to protect against the middle of the field. Still, he is able to trust his feet and hips on vertical or out-breaking routes. He’s also been able to tackle in space well enough to limit gains when he gives up a catch.

Diversity in coverage calls

This is arguably the most important reason McDuffie has been great in this role: that his presence has diversified the coverage looks Spagnuolo can call. In the past two weeks, the Chiefs have had more changes in coverage — and I attribute this to McDuffie’s versatility.

McDuffie has sometimes rotated to be a half-field safety, which helps Kansas City find different ways to get to Cover 2 or Cover 4. He’s also been a critical piece in the Chiefs’ underneath coverage. McDuffie re-routes wide receivers well over the middle of the field, widening them out of their route stems as he passes them to the safeties. When a team runs a play-action pass with a drag route over the middle, McDuffie is also smart enough to robot — that is, bail from his zone to rob the route.

Because McDuffie is versatile enough in all these zone calls, Spagnuolo now has the luxury — depending on the situation — to call both man and zone coverages. This makes defensive tendencies harder to notice. It also makes it more difficult for opposing play-callers to design route concepts to beat either man or zone coverages.

The bottom line

McDuffie has been a home-run draft pick for Chiefs general manager Brett Veach. Since he was injured early in the season, we’ve had a limited sample of his play — but he’s still passed every test with flying colors.

His recent move from outside to the slot — and then thriving there — has been most impressive. That’s just not easy for cornerbacks to do. McDuffie’s ability to excel in both positions speaks to how versatile (and valuable) he is to the defense.

McDuffie’s versatility has also allowed Spagnuolo to do more. With McDuffie in the slot, he can still play man coverage. Since McDuffie doesn’t need any help from safeties, Spagnuolo has more flexibility in how to use them, too. And since McDuffie can drop to play safety — or be a great underneath zone defender — Spagnuolo can call more zone looks.

In the postseason, this will be a critical element. Thanks in large part to McDuffie’s success in this new role, Kansas City will now be able to throw a lot more coverages at opposing offenses — and be able to adjust to whatever they may present.