Lynne Sladky/Associated Press
Antonio Brown is no longer catching passes this season.
Instead, he is trying to win back the roughly $40 million he lost when he was released by the Oakland Raiders and New England Patriots in September.
The N.F.L. Players Association filed several grievances on the wide receiver’s behalf late Friday seeking the unpaid salary and guarantees that Brown did not receive from the two teams, according to two people briefed on the filing.
The grievances by Brown, who is now a free agent, will be heard by an arbitrator appointed by the N.