D.J. Williams and Ryan McBean of the Denver Broncos received six-game suspension without pay last Friday for allegedly violating the NFL's substance abuse policy. In his official statement, Williams disputed the NFL's claim that he substituted a "non-human specimen" in a urine test, and after the league denied his appeal, Williams and McBean have officially filed suit in a Denver District Court to vacate the league's ruling.
Through the league's collective bargaining agreement the arbitration decision in a suspension is typically binding, but in this case the players are alleging that the arbiter was not an impartial party and that he improperly exceeded his powers (a very difficult standard to meet). This bit of additional information comes from Mike Florio of ProFootballTalk.com:
Specifically, they argue (among other things) that Henderson "ignored fatal issues concerning the collection process, safeguarding of the urine specimens and chain of custody," engaged in private communications with the NFL about the case, delayed the ruling at the direction of the NFL, and failed to issue a decision within five days after the hearing.
They seek not only a reversal of the suspensions but a preliminary injunction preventing the suspensions from being implemented while the case is pending.