Which of the following is NOT a reason for filing a non-injury grievance?

Filing a non-injury grievance generally pertains to disputes about benefits, payments, or other contractual issues that do not involve physical injuries sustained by a player. The correct reason for choosing "Player trade disputes" as not fitting into the category of non-injury grievances is that trade disputes are typically handled through league rules and regulations rather than grievance procedures. Trades usually involve broader contractual and league governance issues rather than personal disputes that can be resolved through grievances.

In contrast, injury protection benefits relate to the assurance a player has regarding their financial support in the event of injuries, which can lead to grievances. Disputing incentive bonuses also falls under non-injury grievances as it pertains to the contractual obligations regarding bonuses a player believes they should receive. Similarly, challenges related to suspensions often arise in the context of player rights and behaviors, fitting the grievance framework. However, trade disputes are managed within the league's governance structures, making them distinctly separate from the non-injury grievance processes.