Seattle Seahawks cornerback Richard Sherman claims he failed a drug test because of a "chain of custody" mistake.
Sherman intends to fight his four-game suspension by the league on those grounds, saying his test should be thrown out. He missed two days of practice last week while arguing his appeal. A decision by the NFL is expected some time this week.
The NFL suspended Sherman and fellow cornerback Brandon Browner for four games for allegedly violating the league's substance abuse policy. Browner has already taken his time off. If the NFL upholds Sherman's suspension he will not be able to play in the playoffs.
Sherman played in the Seahawks' win over San Francisco on Sunday. He returned a blocked field goal 90 yards for a touchdown. He also had an interception.