Williams and McBean, suspended without pay for Denver's first six games of the 2012 season, filed their suit Monday in Denver District Court.
Williams' lawyer, Peter R. Ginsberg, said the league contends the urine samples the players provided to an NFL specimen collector for testing in August weren't from a human. But Ginsberg said the specimen collector watched Williams void directly into the specimen bottle, so it would've been impossible for the specimen to be non-human.
The collector has since been fired by the league for dereliction of duty, Ginsberg said, but the hearing officer, Harold Henderson, who works in the commissioner's office, ruled against the players.
The suit from Williams and McBean contends Henderson exceeded his powers and wasn't an impartial arbitrator. The claim could have wider implications for drug cases in the NFL, including the HGH testing policy, which is now in limbo. Players want an independent arbitrator involved any time there is a challenge to a positive drug test, including one for HGH.
But NFL spokesman Greg Aiello said the suit will not succeed.
"The claims have no merit and we are confident that the discipline will be upheld and enforced as required by the policy," he said Tuesday.
The lawsuit claims that errors were made in the chain-of-custody procedure. It also says that, after the players' appeals hearings, the NFL lawyer held what's called "ex parte communications" with Henderson, meaning the players' lawyers weren't present.
"The bottom line is that the NFL totally compromised the steroid policy, trampled on our clients' rights, damaged their reputations, are threatening their livelihoods and we've asked for judicial intervention to ensure against that happening," Ginsberg said.
McBean became a free agent Tuesday afternoon, but with this suspension hanging over his head, his lawyer, Peter Schaffer, wonders just how marketable he will be to teams. Schaffer said the evidence in the case closed on Dec. 9, but he didn't receive a decision until February.
"I want to make emphatically clear that neither one of these players tested positive for a banned or an illegal substance. I think that's very important to point out," Schaffer said. "The damages are enormous. Forget about not just the damage to D.J.'s and Ryan's reputation, but monetarily, it's enormous."
Schaffer also compared the case to that of Milwaukee Brewers outfielder Ryan Braun, who recently won his appeal to overturn a 50-game suspension for a positive drug test.
Braun's legal team argued in a grievance hearing that the collector, Dino Laurenzi Jr., did not follow the procedures specified in baseball's drug agreement.
"The facts of this case are so much better than the facts of Braun," Schaffer said. "In Braun's case, the arbitrator ruled, based on WADA cases, that the collector made a mistake and therefore he can't punish the player, even though Major League Baseball believed the collector did not make a mistake. The collector has come out and said I did everything right and Major League Baseball has come out and said the collector has done everything right.
"In this case, the NFL fired the collector for obvious dereliction of duties. At the hearing, the NFL administrators all admitted the collector made many mistakes and that's why he was fired. And yet they still suspend these two players."
The NFL Players Association also chimed in on the matter Tuesday, questioning the process followed by the NFL before the league suspended Williams and McBean for violating the policy on performance-enhancing substances. The players union said it's "disappointed" with the six-game suspensions.
The union said in its release that there was evidence of breaches in the collection protocol and other procedural irregularities. Also, the NFLPA said the league handed down the bans "even though the specimen collector was fired by his agency for not following procedures."
Williams, who has been the backbone of Denver's defense for several seasons as the Broncos' top tackler, is livid over his suspension, Ginsberg said.
"It's a huge deal professionally and personally," Ginsberg said. "D.J. has been playing for eight years and he's never violated any test for either steroids or illegal substances. Here, the NFL is broadcasting publicly that he failed a steroids test. He's very upset."
Reach out to AP Pro Football Writer Arnie Melendrez Stapleton on Twitter: http://twitter.com/arniestapleton
Reach out to AP Sports Writer Pat Graham on Twitter: http://twitter.com/pgraham34 .