The NFL Players Association filed a non-injury grievance Tuesday challenging the legitimacy of the NFL's new national anthem policy on several grounds.

"The union's claim is that this new policy, imposed by the NFL's governing body without consultation with the NFLPA, is inconsistent with the collective bargaining agreement and infringes on player rights," the NFLPA said in a statement.

The NFLPA, which was not consulted about the anthem policy change, argues in its grievance that peaceful demonstration during the anthem does not qualify as "conduct detrimental to the integrity of and public confidence in the National Football League."

The league will need to rely on the broad powers afforded the commissioner through the personal conduct policy, including applying the phrase "conduct detrimental," to decide whether to fine teams whose players demonstrate on-field during the anthem. NFL fans are accustomed to hearing that phrase as justification for penalizing players accused of illegal or unethical behaviors.

The NFLPA argues that kneeling during the anthem does not qualify as detrimental conduct, evidenced by the fact that the league has said players have the right to use their platform to elevate issues important to them. The players' association believes that allowing peaceful demonstrations to be grounds for detrimental conduct discipline would set a terrible precedent, which teams could use to penalize players for other peaceful demonstrations, including prayer.

The NFL did not immediately comment about the union's filing.

The NFLPA is challenging the NFL's new national anthem policy, saying players protesting during the anthem does not constitute detrimental conduct. AP Photo/Rick Scuteri

At NFL owners meetings in May, the league voted to approve a policy that requires players and team personnel on the sideline to stand during the national anthem. Players have the option to stay in the locker room while the anthem is played. The NFL wrote and ratified the policy without input from the players, as the game operations manual is not part of the collective bargaining agreement.

Commissioner Roger Goodell said the NFL wants to "treat this moment in a respectful fashion." Should the league determine that a player is in violation of the new policy, the team will be fined. Teams can choose to fine players.

Under Article 43 of the CBA, franchises have the right to implement "reasonable club rules." These rules normally include fines for objectively provable violations, such as missing a meeting or skipping a workout. The NFLPA will also seek an arbitrator's judgment on the reasonableness of team-by-team anthem rules, given the fact that no player has been previously disciplined for such demonstrations.

The NFL will have 10 days to respond in writing to the accusations set forth in the grievance. If the issue is not resolved at that point, the NFLPA can appeal to the notice arbitrator. The grievance will be heard by one of four mutually accepted arbitrators.

The hearing likely will take place within 30 days, but grievances of this nature can take months to resolve; Colin Kaepernick's collusion grievance has been unresolved since its filing in October. The NFL and NFLPA have already agreed to meet later this month to start discussions aimed at a resolution to the anthem issue.

The union has not ruled out the potential of challenging the legality of NFL's anthem policy through cities or states, where statutes could prohibit employers from instituting rules like the anthem policy.