The NFL Players Association officially filed a grievance on Tuesday challenging the league’s new national anthem policy. According to The Los Angeles Times, the union says the policy is inconsistent with the collective league’s bargaining agreement and infringes on players' rights. .
The policy allows players to protest during the national anthem by staying in the locker room, but forbids them from sitting or taking a knee if they're on the field or the sidelines. It was approved by NFL owners at their meetings in May and was imposed without consultation with the NFLPA.
The union has proposed having its executive committee discuss the issue with the NFL rather than proceed with litigation, which the league has agreed to.
Source: LA Times