MINNEAPOLIS - A Minnesota judge temporarily blocked the NFL's suspension of Vikings stars Kevin and Pat Williams on Wednesday for violating the league's anti-doping policy, but whether they can play this weekend remained uncertain.

Hennepin County District Judge Gary Larson issued the temporary restraining order at the players' request, saying he wanted more time to hear arguments in the case. No further hearing date immediately was set.

The Williamses, not related, were among six players suspended for four games for testing positive for the diuretic Bumetanide that can be used as a masking agent for steroids. The players were not alleged to have used steroids. They have argued that the substance containing the diuretic didn't list all of its ingredients, and that league scientists and lawyers had information about the substance but withheld it from players.

The ESPN.com Web site reported Wednesday night that the NFL Players Association will file a lawsuit in U.S. District Court in Minneapolis on Thursday, seeking to overturn all suspensions issued Tuesday by the league for any player who took the substance. The basis for the union's action is founded on many of the same arguments that resulted in the temporary restraining order issued in the state district court.

The NFL argues that the league's policy on banned substances is collectively bargained with the players' association and players are responsible for what is in their bodies.

"This is one of the more difficult cases I've had in 23 years," Larson said before signing the order. "If I make a mistake, I've got to decide on a temporary basis which side I'm able to make the mistake on."

Larson said he expected lawyers for the NFL, who participated in the hearing by phone, would take the issue to federal court in Minneapolis to get the suspensions reinstated.

"There is no merit to this lawsuit and we will promptly seek to have the order reversed," the NFL said in a statement.

New Orleans Saints players Deuce McAllister, Will Smith and Charles Grant, who already was out for the season with an injury, appealed their suspensions.

The sixth player suspended was long snapper Bryan Pittman of the Houston Texans.