Le'Veon Bell is reportedly facing a four-game suspension for missing a required drug test, and while the Pittsburgh Steelers running back denied missing any drug tests last month, NFL Network's Ian Rapoport reports that Bell's potential suspension is the result of "several" missed drug tests.

Bell, who is already in the NFL's substance-abuse program, was suspended for the first two games of the 2015 season after being arrested for marijuana possession and DUI. Players who are in the league's drug program are subject to frequent testing, which they are required to make themselves available for. While Bell plans to appeal the suspension, he would be in clear violation of the policy by missing multiple tests, making it difficult to argue his case.

In his three seasons in the NFL, Bell has rushed for 2,777 yards and 19 touchdowns, averaging 4.3 yards per carry. He was a first-team All-Pro and a Pro Bowler in the 2014 season.

More from FoxSports

If Bell is indeed sidelined for any amount of time, DeAngelo Williams would be the Steelers' No. 1 back. Williams rushed for 907 yards and 11 TDs last year, his first season with Pittsburgh.