Yeah, I was going to say that subs only happen when players are tired (red). If you notice a player isn't that wasn't red, check your current formation. The reason I say that is because there's a formation in the Raven's playbook (sub flex) that takes Ngata off the field, even though he is not fatigued. It's just because the formation uses an extra cb instead of a lb, and a lb instead of a linemen.
As for whether the lbs subbed, I don't want to feed you a wrong answer, so let me play again to check.