The labor federation filed a friend of the court brief on Monday asking the 2nd U.S. Circuit Court of Appeals to reconsider a decision handed down by a three-judge panel in April.
Brady was suspended four games for what the league said was a scheme to use improperly inflated footballs in the 2015 AFC Championship game. NFL Commissioner Roger Goodell rejected his initial appeal, and Brady appealed to the federal courts.
In the brief, the AFL-CIO says Goodell "acted arbitrarily as an employer seeking to justify his own disciplinary decision rather than as a neutral arbitrator considering an appeal."