What distinguishes a player as being subject to waivers?

A player is distinguished as being subject to waivers primarily based on credited seasons. In the NFL, waivers are a mechanism that allows teams to release players and have other teams have the opportunity to claim those players. The number of credited seasons a player has affects their eligibility for waivers. Generally, players with fewer credited seasons are subject to being placed on waivers when they are released, while those with greater experience or time in the league might have different processes following their release.

This understanding of credited seasons plays a crucial role in a player's career and their potential for being claimed by other teams. A player with a lengthy tenure in the league might not go through waivers if released, instead becoming a free agent, allowing them greater freedom in choosing their next team. Thus, the focus on credited seasons is what primarily defines a player’s status in relation to being placed on waivers, making it the correct choice for this question.