The NFL Players Association has filed a pair of grievances challenging the authority of NFL commissioner Roger Goodell to suspend four players for their involvement in the New Orleans Saints' bounty program.

In the first, filed with arbitrator Shyam Das, the NFLPA argues that Goodell is prohibited from punishing players for any conduct prior to Aug. 4, when the current collective bargaining agreement took effect.

"In connection with entering into the 2011 CBA, the NFL released all players from conduct engaged in prior to the execution of the CBA, on August 4, 2011," the grievance says.

The section of the CBA cited by the union is a covenant not to sue -- an agreement in which the NFL and its teams pledged not to file lawsuits against the union and its members "with respect to conduct occurring prior to the execution of this Agreement."

But the league said that section of the CBA was not intended as an agreement to excuse player conduct that put player safety at risk, or conduct detrimental to the NFL.

The NFLPA further argues that even if that argument fails, the appeal of the player suspensions should be heard by Ted Cottrell and Art Shell, the hearing officers for on-field conduct violations, rather than by Goodell as an off-field conduct issue.

In the second grievance, the NFLPA argues that arbitrator Stephen Burbank, who serves as the "system arbitrator" for the league and its players' union, has the authority to rule on the players' conduct, rather than Goodell.

Burbank, a law professor at the University of Pennsylvania, is the same person hearing a grievance brought by the Washington Redskins and Dallas Cowboys over penalties assessed by the NFL for alleged violations of the league's salary cap.

According to the NFLPA grievance, the bounties, as non-disclosed payments to players, are a collective bargaining issue under the jurisdiction of the arbitrator and not Goodell.

In a statement, NFL spokesman Greg Aiello said the league expects the arbitrators will "reject the union's efforts to protect players from accountability for prohibited and dangerous conduct directed against other players," as well as uphold the disciplinary process which was set forth in collective bargaining last summer.