The motion filed Wednesday before the 8th U.S. Circuit Court of Appeals indicates the NFL will challenge a three-judge panel's ruling allowing the Williamses to play.
The league had tried to suspend the players for testing positive for a banned diuretic, but the players contended they didn't know the weight-loss supplement they took contained the substance.
The players also argued that the NFL was aware of the supplement's ingredients and failed to tell players.
The appeals court clerk has given the NFL until Oct. 9 to file a petition for a rehearing.