Bryant previously served a one-year suspension in 2016.
Former Steelers receiver Martavis Bryant is facing a one-year suspension for violating the NFL's substance abuse policy per ESPN's Adam Schefter.
A year-long ban would mark Bryant's third suspension in four years, and his second full-season suspension. The Clemson product missed the entire 2016 campaign for a substance-abuse violation.
The looming suspension continues a tumultuous year for Bryant. The former fourth-round pick was traded from Pittsburgh to Oakland in exchange for a third rounder in April, but was released by the Raiders on Sept. 1.
Bryant tallied 126 receptions in three seasons with Pittsburgh. He caught 50 passes for 603 yards last year, adding three touchdowns.