Dr. John Lombardo, who oversees the league's steroids policy, "expressly knew and willfully withheld the critical information that StarCaps secretly contained the banned diuretic substance," the filings allege. They also allege that NFL vice president Adolpho Birch, who also oversees the policy, also knew but withheld the information that StarCaps "contained a prohibited substance that could jeopardize the health and career of any player who used the product."

According to the filings, during the players' arbitration hearings last month a consulting toxicologist for the league, Dr. Bryan Finkel, testified Lombardo told him he did not disclose what he knew because he wasn't sure whether all StarCaps products contained the banned drug. Finkel also said he was afraid the supplement manufacturer might sue him if he made a public statement against the product.

But Birch testified during the arbitration hearings that he did not notify any teams, players or the union in writing that StarCaps contained bumetanide, the memo shows.

The NFL has said it sent two notifications about StarCaps on Dec. 19, 2006 — one to NFL club presidents, general managers and head athletic trainers and the second to NFLPA executive Stacy Robinson, who oversees the steroid policy for the union. That letter, according to the league, advised that the makers of StarCaps had been added to the list of prohibited dietary supplement companies.

In announcing the suspensions Tuesday, the NFL said it's not obligated to issue specific warnings about specific products. The league also reiterated the section of its policy that reads:

"You and you alone are responsible for what goes into your body. Claiming that you used only legally available nutritional supplements will not help you in an appeal. ... Even if they are bought over-the-counter from a known establishment, there is currently no way to be sure that they contain the ingredients listed on the packaging or have not been tainted with prohibited substances ...

"If you take these products, you do so AT YOUR OWN RISK! For your own health and success in the league, we strongly encourage you to avoid the use of supplements altogether, or at the very least to be extremely careful about what you choose to take."

Kevin and Pat Williams had already obtained a temporary restraining order blocking their suspensions from Hennepin County District Judge Gary Larson on Wednesday. Thursday's lawsuit would protect all five players and had no immediate effect on Larson's order.

In the sixth case, Cornwell said he reviewed Pittman's case with the NFLPA, the player and his agent, Kevin Gold.

"While we remain disappointed in the result, we concluded that, under the circumstances, the chances of a successful challenge were not favorable," Cornwell said.

A seventh player under scrutiny, Atlanta's Grady Jackson, has not been suspended. Jeff Pash, the league's chief counsel, has asked for additional information.

Jackson filed suit against StarCaps in California last month, seeking restitution for any lost salary and damages for "false advertising and unfair business practices."

McAllister said Tuesday that he told other players about StarCaps because he believed it was a permitted supplement.

"I wouldn't have put those guys in jeopardy if I had known something was in that product," he said.