Henderson suspended four games
The suspension covers Minnesota's final three regular-season games and first playoff game. The NFL does not specify the substances for which players test positive.
A message was left seeking comment from Henderson's agent, Brian Mackler.
The Vikings were off Tuesday and unavailable for comment.
Henderson is the younger brother of fellow linebacker E.J. Henderson, who broke his left leg Dec. 6 and is out indefinitely.
Erin Henderson has been active for only two games this season, including Sunday's win over Cincinnati. He has played primarily on special teams since signing with the Vikings as an undrafted free agent in 2008 and had two special teams tackles against the Cincinnati Bengals.
The Vikings have had several run-ins with the league for alleged use of performance-enhancing drugs.
In 2007, defensive end Ray Edwards was suspended for four games for violating the policy.
The NFL has been fighting for the right to impose four-game suspensions on Vikings defensive tackles Kevin Williams and Pat Williams. They tested positive in 2008 for the diuretic bumetanide, which the NFL prohibits because it can mask the presence of steroids. The Williamses, who are not related, ingested the banned drug when they took the weight-loss supplement StarCaps, which did not state on the label that it contained bumetanide.
The NFL has been unable to persuade the courts so far that federal labor law and the league's collective bargaining agreement should trump Minnesota state laws regarding drugs in the workplace. After losing its latest round in a federal appeals court on Monday, NFL spokesman Greg Aiello said the league was considering an appeal to the U.S. Supreme Court. The Williamses' suspensions remain on hold pending the outcome of their lawsuit in state court in Minnesota, which seeks to block the suspensions permanently and is set for trial March 8.
With E.J. Henderson's injury and Erin Henderson's suspension, the Vikings (11-2) are thin at linebacker. Minnesota signed J Leman from the practice squad on Tuesday to take Erin Henderson's place in the linebacking corps and signed cornerback DeAndre Wright to the practice squad.
Copyright 2009 by The Associated Press