C.J. Mosley was playing a brilliant game for the Jets against the Buffalo Bills on Sunday before leaving during the second half with a groin injury.

Trailing 16-3 in the fourth quarter, the Bills went on an 85 yard touchdown drive shortly after Mosley left. Buffalo rolled down the field with a particularly dominant effort on the ground. Four rushes on the drive netted Buffalo 7 yards or more.

Naturally this left many assuming a cause and effect. Mosley left the game. The Bills immediately had success on the ground.

I was a little skeptical. My hunch was that Mosley’s absence likely had some impact, but it likely couldn’t explain everything.

After reviewing the drive, I think that theory holds up.

Frank Gore runs for 7 yards.

This is the one run play where I think Mosley’s absence made a clear difference because one of the main culprits, Blake Cashman, was Mosley’s replacement.

Cashman takes a couple of false steps into the A gap hole, which makes him easy to seal for a pulling guard when Gore bounces the run outside.

Devin Singletary runs for 23 runs

On this play it’s less clear Mosley would have made a difference. Tarrell Basham (yellow) and Jamal Adams (red) get taken out by pulling interior linemen, while Neville Hewitt (pink) gets sealed by a tight end.

Adams (red) probably gets out too wide and makes himself easy pickings.

Devin Singletary runs for 12 yards

On this play Leonard Williams (pink) just missed shedding his block on time to drop Singletary for a loss. Williams is able to force Singletary to bounce outside. Unfortunately Basham (yellow) is blocked by a tight end, while Adams (red) is sealed by a wide receiver.

Devin Singletary runs for 15 yards

On this play Harvey Langi (pink) gets himself shoved inside. Adams (red) again get himself out really wide and makes himself an easy block for the pulling center. A cornerback like Brian Poole (red) has little chance against a pulling guard.

What does this tell us?

This wasn’t the only Buffalo scoring drive of the game. The Jets still led after the drive. These also aren’t the only plays the Bills made. There were a few more modest runs and gains made through the air.

Still this series was striking because Buffalo rolled down the field and gashed the Jets in the run game right as Mosley left.

So how much did the Jets miss Mosley?

The Cashman play shows us Mosley likely would have made some degree of difference. Beyond that? We are entering the realm of speculation. It’s possible some of the defensive playcalls are different with Mosley in there. On the play with Hewitt, maybe he lines up there. Maybe he flies to the ball on some of these plays to bail people out. (He certainly was playing a big impact game so we can’t rule it out.)

With that said I don’t think it’s possible to conclude C.J. Mosley’s departure is the one and only reason the defense fell apart on this drive. Frequently the answer lies between the extremes. This is likely one of those cases. His departure wasn’t irrelevant. It wasn’t the only explanation.

I tend to think there were bigger issues. The Jets need to do a much better job of setting the edge than they did on this series. And neither that nor Mosley’s departure might have even mattered had the best run stopping safety in football made the plays in front of him.

Even then, the Jets had the lead after this drive. The game wasn’t lost until their suspect corner play was exposed, and that is not Mosley’s domain.