What is the primary role of a linebacker in a defensive lineup?

The primary role of a linebacker in a defensive lineup is to defend against both the run and pass. Linebackers are pivotal to the defensive strategy, as they are positioned behind the defensive line and have the versatility to participate in various defensive schemes. They are responsible for reading the offense, filling gaps to stop running plays, and also dropping back into coverage to counteract passing plays. This dual capability makes them crucial to the defense's overall effectiveness, allowing them to respond to different offensive formations and plays.

In contrast, focusing exclusively on the run or only rushing the quarterback limits their ability to adapt and respond to the offense, which is why those other options do not accurately capture the complete role of a linebacker. Consideration of both aspects—the run and the pass—highlights the linebacker’s importance in balancing their responsibilities on the field.