But the league's policy on anabolic steroids and related substances is quite clear.

Here's an excerpt: "The use of so-called 'blocking' or 'masking' agents is prohibited by this policy. These include diuretics or water pills, which have been used in the past by some players to reach an assigned weight. ... Players are responsible for what is in their bodies."

The NFL has a medical expert authorized to field questions from players regarding specific supplements. It also has a toll-free hotline players can call.

"They get a list of what's in and what's out," Minnesota coach Brad Childress said. "But it's up to them, once again, whether they're reading labels. I mean, strict liability is strict liability."

Fox Sports has reported that the Williamses, who both made the Pro Bowl last season and anchor the Vikings' stout run defense, are facing a four-game suspension for failing a drug test.

The Associated Press has reported that six to eight players around the league are appealing findings that they took a weight-loss diuretic considered a masking agent for steroids.

Four players have already received four-game suspensions for violating the policy this season, and all of them claimed they unknowingly took products that were illegal. But the NFL's guidelines don't appear to allow for any grace for maintained innocence.

Safety Darren Sharper, the team's union rep, concurred with his coach.

"That's up to us. That's our job. You have to look at the list and see what's on it," Sharper said. "Mistakes can't happen."

Vikings defensive end Ray Edwards, who served a four-game suspension last December for an unidentified substance, said he didn't bother appealing his punishment because he "knew there was no chance" of him winning it. He also wanted to get it over with as quickly as possible so he could return for a possible playoff game.

Edwards also expressed the need for players to be extra careful about what's in the products they take to enhance their bodies, even if there's no intent to cheat.

"This is our job. We just have to make sure we protect ourselves. That's about it. That's all I'm saying," he said. "I had the situation last year. You've just got to protect yourself."

That the names of the Williamses, plus a handful of others around the NFL, have been leaked to the media is another violation of league policy. It states that the "confidentiality of players' medical conditions and test results will be protected to the maximum extent possible" and "any club or club employee that publicly divulges, directly or indirectly, information concerning positive tests or other violations of this policy ... is subject to a fine of up to $500,000 by the commissioner."

League spokesman Greg Aiello had no comment on the report.

Childress acknowledged concern about the breach in confidentiality, which has created an extra distraction for his team well ahead of an actual announcement of punishment.

"That's one of the mandates of the policy," he said. "That's why I'm not talking about it. ... It's supposed to be held in strict confidence, so from the standpoint that somebody knows that shouldn't know, I'd say that that's not good."