Aaron Glenn on QB Spy: Watch Film and See What Happens to Teams

Exploring if Detroit Lions should use quarterback spy against Cardinals.

Detroit Lions defensive coordinator Aaron Glenn / Junfu Han / USA TODAY NETWORK

One of the biggest keys to success this week will be for the Detroit Lions defense to contain Arizona Cardinals quarterback Kyler Murray, tackling well and making sure the speedy quarterback does not take over the game via the ground.

Through two games, Murray has presented problems for opponents both with his arms and legs. He has scrambled 10 times for 116 yards while throwing for 428 yards and four touchdowns.

Because of the diversified offensive attack, defensive coordinator Aaron Glenn is cautious to deploy a linebacker spy on Murray throughout Sunday's game.

“You see Buffalo do it. What happened? We have to do a really good job keeping him contained," Glenn said. "That could be quarterback spy, that could be rushing five, that could be rushing six. The fact of the matter is you have to keep him contained. I know that’s the in vogue thing that everybody talks about, quarterback spy, quarterback spy. I wish you guys would actually look at the film and see what happens when that happens for the most part.” 

Detroit's defensive coordinator understands a linebacker is assigned to mirror a quarterback's every move. It typically vacates the middle of the field, and can leave a defense exposed for larger gains should a quarterback evade the pocket.

The Buffalo Bills were unsuccessful, as Murray ran for 57 yards on five carries.

The argument for the spy working would be that the assigned defender could limit Murray's opportunities outside of the pocket. However, discipline is a key element as losing contain could result in big plays, either by Murray or over the middle of the field if the spy is forced away.

In the below clip, Murray faces a spy from the Bills, linebacker Dorian Williams. Williams tries to mirror Murray, but the quarterback scrambles outside of the pocket. Williams gets blocked, and Murray is able to run upfield for a modest gain and draw a penalty.

Dan Campbell explained to reporters this week the Cardinals starting signal-caller is "dangerous" and has been successful running the offense moving the pocket at times.

"I really like what they’re doing with him, and I think so much of his game when he was coming out of college was, ‘Hey, he’s in the gun, put him in the gun, that’s what he’s done.’ And you’re playing the spread game, which, there’s nothing wrong with that, but this unit comes in and the approach is a little bit different," said Campbell. "Certainly, they’re taking a portion of that, but they’re a little bit heavier in the run game with it, 12-personnel, 13-personnel.

"The fact they’ve incorporated under center with it and the heavy runs with boots off of it, really hard action, get him out of the pocket completely, let him see the field and if it’s not there you see what he can do with his feet," Campbell continued further. "So, I just think it’s good, man, it’s allowed them to really control the game."

Last week, the Cardinals torched the Rams defense, en route to a 41-10 victory.

"They can control the game if you let them, and I think it’s been good for him, it’s right up his alley. I mean, look at last week, 17-of-21, I mean, 17-of-21, 266 yards, three touchdowns," said Campbell. "I mean, he got a perfect quarterback rating. So, I just think it fits him well, I think they’re still using the things that he can create problems out of the gun, the read run, the zone run stuff, but then they can just downhill beat you up if they want."

Campbell expressed it was remarkable just how many missed tackles Murray forced last week.

"I think it fits him well and they don’t want to ask him to do everything, but if the opportunity presents itself to where he needs to run around and make somebody miss," said Campbell. "I mean, I don’t know how many missed sacks, missed tackles he avoided last week. I hadn’t counted them up yet, but that’ll be a project for me tonight because it was unbelievable. I mean, it’s just time after time after time. So, he’s dangerous, man, he’s dangerous.”