Which player position must meet specific requirements to be eligible on the line of scrimmage?

The position that must meet specific requirements to be eligible on the line of scrimmage is primarily the offensive player. This is because offensive players must adhere to certain regulations regarding their formation and alignment in order to be eligible to receive the snap and participate in the play. For instance, to be eligible, specific players must be lined up in certain positions, such as having a certain number of players on the line of scrimmage or having them meeting the criteria of being an eligible receiver.

While defensive players and quarterbacks have their own sets of regulations, it is the offensive players who have clearer and more defined requirements imposed on them when they are set to snap the ball. Quarterbacks, while classified as offensive players, follow the broader rules designed for the entire offensive unit. Therefore, focusing on overall offensive player eligibility aligns with the correct understanding of the rules governing player positions relative to the line of scrimmage.