PITTSBURGH, PA (WCMH) – Pittsburgh Steelers running back Le’Veon Bell is facing a four-game suspension for violating the NFL’s drug policy, sources tell ESPN and NFL.com.

The sources told ESPN the suspension is for missing several drug tests.

NFL’s Ian Rapoport confirmed the reports.

Bell is in the process of appealing the suspension. The running back was also suspended for two games at the beginning of the 2015 after a DUI arrest. He also spent a significant part of the season out with a knee injury.

The Steelers went 7-3 in the 10 games Bell missed.

When healthy, Bell is one of the most dynamic backs in the league. Yet he’s seen each of his past two seasons end with knee injuries suffered against the Bengals. The team has yet to approach him about a new contract as he enters the final year of his rookie deal. Bell insists the uncertainty about his future won’t be a distraction. He just wants to play.The Associated Press contributed to this story.