ST. PAUL, Minn. – A federal judge on Friday blocked the NFL from suspending five players for violating the league's anti-doping policy by using a banned diuretic, clearing the way for them to play Sunday.

In this Oct. 7, 2008, file photo, New Orleans Saints defensive end Will Smith is shown during a football game against the Carolina Panthers at the Superdome in New Orleans. The NFL Players Association is suing to block five of the six player suspensions for violating the league's anti-doping policy. The suit filed in federal court is on behalf of Kevin Williams and Pat Williams of the Minnesota Vikings, and Charles Grant, Deuce McAllister and Will Smith of the New Orleans Saints. (AP Photo/Alex Brandon)

U.S. District Judge Paul Magnuson said he needed more time to consider the case after hearing several hours of arguments from the league and the NFL Players Association.

"I've got to read the background material," said Magnuson, who noted he received a 20-page filing from the NFL earlier that morning. "Justice cannot function in this way."

Magnuson gave no indication when he would issue his written ruling, but did note there was no evidence of steroid use by the players. "We're not talking about steroids in this case. Period," he said.

Kevin Williams and Pat Williams of the Minnesota Vikings and Charles Grant, Deuce McAllister and Will Smith of the New Orleans Saints were suspended this week for four games each. They tested positive for a banned diuretic in the dietary supplement StarCaps.

The union argued the NFL didn't properly inform players about what it knew about the product. The NFL's attorneys argued that that claim, and others, had been considered and rejected in a process set out by the league's collective bargaining agreement.

"The arbitrator's decision carefully goes through each and every one of these things," said NFL attorney Dan Nash.

NFL spokesman Greg Aiello said the league welcomed the scrutiny Magnuson was giving the case.

"We are confident that, once he has had an opportunity to review all of the relevant materials, including the collective bargaining agreement, he will uphold our long-standing agreements with the (NFL Players Association) that protect the health and safety of NFL players and the integrity of our game," Aiello said.

Jeff Kessler, an attorney for the union, said he was delighted. He said the ruling showed that the NFL isn't above the law. "In this particular case, they did not follow the rule of law," Kessler said.

Magnuson's move came two days after a Hennepin County judge issued a restraining order blocking the Williamses' suspension. The NFL got the case moved to federal court, where the NFL Players Association joined in a broader action that included the Saints players.

The five players were suspended for four games for testing positive in training camp in July and August for the banned diuretic Bumetanide, which can be used as a masking agent for steroids. Diuretics are also used to quickly shed weight.

The drug was in the dietary supplement StarCaps even though the label did not list the diuretic as an ingredient.

Attorneys on both sides told Magnuson overweight players use the weight-loss drugs for various reasons, including getting down to target weights in their contracts and for medical reasons, including alleviating high blood pressure and heart problems.

The key issue is whether the NFL had any specific obligation to notify players and the union that it had known since at least 2006 that the weight loss supplement contained the banned diuretic. The NFL says the burden is on players to know what's going into their bodies.

Kessler argued Friday that the NFL did not properly inform the players about a "potentially killing substance" because it can lead to dehydration. The union had claimed that Dr. John Lombardo, who oversees the NFL's steroids policy, in consultation with the league's attorneys, withheld critical information on StarCaps containing the banned diuretic.

Nash argued that Lombardo had made a professional decision to warn players in general about diuretics rather than specifically about StarCaps. Further, he argued the players should complain about Lombardo in negotiations with the league — not in court.

Kessler also argued that there was no reason the suspensions couldn't be delayed further. He pointed out that the tests were conducted during training camp in the summer, and months passed before this week's suspensions.

"All we are trying to get is a little more time," Kessler said. "There is no damage to them. There is tremendous damage to the players," who have short careers and could be robbed of a chance to make the playoffs.

Nash argued that delaying the suspensions would damage the collective bargaining agreement. And he disputed the idea that the league was responsible for the timing of the suspensions.

"We have been accommodating the players and their lawyers all season," he said.

Kevin and Pat Williams, who aren't related, are star defensive tackles for a Vikings team that is 7-5 and in first place in the NFC North. They play Detroit on Sunday. The Saints are last in the NFC South, two games out of the wild card spot with four games to play.

What happens next will depend on Magnuson's ruling, Kessler said. The judge could uphold the arbitrator's decision and let the suspensions stand, order the arbitration process to start over with a different arbitrator or — if he finds the league violated good public policy by withholding its information about StarCaps — nullify the suspensions entirely.

Kevin Williams is second on the team with 8 1/2 sacks, while Pat Williams is the chief run-stuffer for the league's second-ranked rushing defense. They both declined comment on the situation during media availability after practice, before the ruling was announced.