Carolina Panthers defensive end Julius Peppers, a prime contender for NFL rookie of the year, was suspended by the league yesterday for four games under the league's policy on steroids and related substances.

Peppers was told by the league that he had tested positive for a banned substance in a dietary supplement, according to his agent, Marvin Demoff.

The Associated Press reported Peppers did not test positive for steroids. The Charlotte Observer, citing an unnamed source, reported yesterday that Peppers had what was described as "an abnormal test."

Peppers, who was selected second overall from North Carolina and leads the league with 10 sacks, plans to appeal the automatic four-game suspension mandated by the policy, so he can play in Sunday's game against Tampa Bay.

In a prepared statement, Peppers said: "While I would like to provide the fans with more information, due to the legal ramifications I cannot comment on the situation and I will not be able to until the appeal process is complete."

An NFL spokesman said the league would not comment. ESPN.com reported that two sources said the substance was either ephedrine or a derivative of the stimulant ephedra. The Observer said a source indicated Peppers has denied taking any banned substances.

The NFL has banned those substances, often found in dietary or weight loss supplements and over-the-counter cold medicines, for the first time this season. All teams have informed players about the banned substances, and trainers have been urging players to ask if they're not sure.

Peppers signed a seven-year contract estimated at $62 million if he meets all incentives, and is playing on a $1 million base salary this year. If suspended, he would lose $235,294 in compensation. Many players also earn incentives for winning statistical titles or postseason honors. If Peppers does not lead the league in sacks or fails to get rookie of the year, the cost to him could reach seven figures.

Another Carolina player, defensive tackle Brentson Buckner, is serving a four-game suspension for violation of the new policy. He tested positive for ephedra after taking a dietary supplement.