The attention deficit hyperactivity disorder medication Adderall has become the excuse du jour for players testing positive for a banned substance in the NFL. Seattle Seahawks cornerback Richard Sherman insists it's not just an excuse.

Sherman successfully appealed a four-game suspension last season due to a mishandled sample.

"About half the league takes it, and the league has to allow it," Sherman told Vancouver Sun reporter Mike Beamish on Tuesday. "The league made a mistake in my case. Obviously, I didn't do anything, but you have to go through a process to prove you didn't do anything. There are still naysayers out there who don't believe me. But I accept it. If everybody loves you, it probably means you're not much of a player."

Players are allowed to take Adderall only if approved by the league for medical reasons. The league would like the NFL Players Association to agree to more transparency with the public and wants to list the banned substance when a player fails a test. Why?