Two of the six players suspended by the NFL for testing positive for drugs are preparing to challenge the ruling.

A source with knowledge of the case told PA Sport today that a legal procedure was being prepared by New York-based attorney Peter Ginsberg.

Defensive tackles Pat Williams and Kevin Williams of the Minnesota Vikings, a trio of players with the New Orleans Saints - running back Deuce McAllister and defensive ends Will Smith and Charles Grant - and centre Bryan Pittman of the Houston Texans were slapped with four-game suspensions for violating the league's policy on anabolic steroids and related substances.

Attorneys for both Williamses were in Hennepin County District Court in Minneapolis this afternoon seeking a restraining order to allow both Minnesota tackles to continue playing, a spokesman for the court confirmed to PA Sport.

NFL spokesman Greg Aiello said his office was not aware of any pending legal action.

The drug in question is Bumetanide, a diuretic which can mask the presence of other substances, including steroids.

Attorneys for the Williamses are expected to argue that league officials were aware that StarCaps, a product used by the players, contained bumetanide but failed to share that information with players.

The league, however, seemed to leave little room for such an argument in spelling out its policy to the players in the statement which announced the players' suspensions.

"You and you alone are responsible for what goes into your body," the policy read. "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."

Defensive tackle Grady Jackson of the Atlanta Falcons also faces a four-game suspension but the Falcons said his appeal has been deferred pending additional information requisition by NFL Chief Counsel Jeff Pash.

"The players specifically violated a long-standing provision of the policy relating to the use of diuretics and water pills, which serve as masking agents for steroids and are potentially dangerous to the health of players," the NFL statement read.

The suspensions were a severe blow to the NFC North-leading Vikings, who lost the heart of their interior line with the suspensions of the Williamses, who are both Pro Bowlers.

"In response to this afternoon's ruling, the Minnesota Vikings are very disappointed in the National Football League's decision and suspension of Kevin Williams and Pat Williams," the team said in a statement. "At the appropriate time, we will have further comment."

The Saints, who are teetering on the edge of play-off elimination, also lose a pair of players with the expulsions of Smith and McAllister. Grant was placed on season-ending injured reserve last month.

With four games remaining, the suspensions effectively end the regular season for the players. However, if a player's team makes the post-season, he is eligible to return to the active roster on Monday, December 29.

During their appeals, the players attributed the positive tests for taking the weight-loss supplement StarCaps, which does not list Bumetanide as an ingredient.

David Cornwell, a Washington-based attorney who represented the Saints players during their appeals, argued that Dr John Lombardo, the administrator of the NFL's policy regarding anabolic steroids and related substances, was aware that StarCaps contained Bumetanide but did not share the information with NFL players, fearing that players who testing positive for the drug would claim they took StarCaps even if it were not true.

The league addressed that argument in its statement.

"With respect to the question of whether a specific warning should have been given regarding StarCaps, the policy does not set forth an obligation to issue specific warnings about specific products and no testimony suggests that the NFL and NFLPA have ever contemplated imposing such a requirement on Dr Lombardo, who oversees the development of education materials on steroids," the statement read.

Citing other policies, the league noted that the United States Anti-Doping Agency (USADA) does not issue specific warnings about specific supplements, nor are such warnings issued in other drug testing programs.

Atlanta's Jackson, in fact, has filed a class-action lawsuit against the Nikki Harrell's StarCaps diet pills - the manufacturer of the diuretic.

The company acknowledged the lawsuit in a message posted on its website, StarCaps.com.

"We've received notice of a problem with an NFL player," the statement read. "We have referred the matter to our counsel and are taking all necessary steps to ensure that our customers receive product that is safe and effective. We have temporarily suspended shipping of StarCaps pending the results of our investigation."