"A cornerstone of both of our drug testing programs has always been that you are responsible for what is in your body," Greg Aiello, NFL senior vice president of communications, said via email Tuesday. "It is stated that way in the policies."
Sources told ESPN NFL Insider Adam Schefter that Gordon will attribute his one positive sample to secondhand smoke, and that he also will argue a disparity in the two samples he provided.
No player has won an appeal based on secondhand smoke.
In addition, several other players have been suspended for "not being responsible for what is in your body," as Aiello described.
Gordon himself is one example. A year ago, he said he tested positive for codeine in his prescribed cough medicine. Codeine is a banned substance, and he was suspended because he was responsible for knowing what he was taking. The four-game suspension was negotiated to a two-game ban and four games without pay.
Adolpho Birch, the NFL vice president of labor policy and government affairs, has said often that players can reach out to the league before taking any drug to ensure it does not contain a banned substance. Once a positive test comes back for substance-abuse drugs, the league follows rules agreed to in the collective bargaining agreement.
Gordon has hired high-powered attorney Maurice Suh to represent him at Friday's appeal, which will be in New York.