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.

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.