As I’m sure you are all aware of by now, the Lions will be without their starting middle linebacker Stephen Tulloch for the rest of the year due to tearing his ACL after celebrating a sack. He would play one more down after the sack, but seemed to re-injure his knee after being engaged with a blocker on the next drive. Some may view it as a bone-headed move, but it was mostly just a freak accident that may haunt the Lions for the rest of the year.

Let’s take a closer look at the play that ended Tulloch’s season.

NFL Game Rewind

In the play above, the Lions are lined up in a 3-3-5 defense with two-deep coverage. This is something we haven’t seen quite that often, but we’ll likely see more of in Teryl Austin’s scheme.

As you notice, the Lions have Ndamukong Suh lined up as if he’s a nose tackle in the zero-technique, along with Jason Jones and George Johnson posing as two 3-4 defensive ends lined up past the opposing tackles in the five-technique. Ezekiel Ansah is actually lined up in a two-point stance posing as a blitzing linebacker on the weak side of the field while Tulloch and Levy stay back and cover the running back and tight end respectively.

As the play starts to develop, Tulloch will find that the running back is staying back to block and pick up Ansah’s blitz, so he decides to pursue the QB. The right guard fails to see Tulloch coming through and instead decides to double team Johnson to his right, leaving an open lane for Tulloch to weave his way through and sack Rodgers to force a punt.

This sack is what we call a “green dog” technique.

When watching this play live, many (including myself) will call it a delayed blitz, but in reality you don’t normally see delayed blitzes called in two-man defense. Tulloch is simply reacting to the blocking RB who is his coverage responsibility.

Here is a quote taken from SB Nation’s Football Study Hall about the Green Dog technique.

The point of a Green Dog is to add an extra man, late into the play, when a man-to-man coverage blitz is called by the defense. A simple example of a Green Dog occurs when a linebacker is supposed to cover the running back man-to-man when a blitz is called. If the running back stays in to help pick up the blitz, the man in coverage then becomes an additional blitzer – that is a Green Dog. On a Green Dog, the responsibility of the linebacker who was originally in coverage changes, and he is asked to become another blitzer in the pressure scheme.

Tulloch has made a living off of delayed blitzes and the Green Dog blitz during his tenure with the Lions, and it will be sorely missed. With Tahir Whitehead replacing Tulloch at the middle linebacker position, we’ll surely see some mistakes as Whitehead is already young and inexperienced, but switching to the MIKE is no easy task.

Last week when Tulloch suffered his injury, DeAndre Levy was given a microphone in his helmet to call plays at the outside linebacker position and the defense didn’t skip a beat against the Packers. It will be interesting to see whether that will continue, or whether Whitehead will take over those duties.

Whitehead has shown a ton of promise for the Lions already this year, but he has some pretty big shoes to fill right now.