Former Buffalo Bills running back Karlos Williams, who was surprisingly cut by the team before the 2016 season following a promising rookie campaign, has been suspended by the NFL for a period of at least one year after a third substance-abuse violation, a league source said.
Williams already had one game left on a 10-game suspension for violating the NFL's substance-abuse policy.
He currently is a free agent after being waived by the Pittsburgh Steelers this offseason.
A fifth-round pick by the Bills in 2015, Williams played in 11 games as a rookie, starting three. He gained 517 yards on 93 carries and scored seven rushing touchdowns in addition to two receiving touchdowns.
He tied an NFL record in 2015 by scoring a touchdown in each of his first six games played in the league. Patriots running back Robert Edwards also scored touchdowns in his first six games as a rookie in 1998.
Williams began 2016 training camp on the Bills' active/non-football illness list after he reported to minicamp in June out of shape.
He was suspended for the first four games of that season for a substance-abuse policy violation and was ultimately released by the Bills on Aug. 21.
The Steelers then signed Williams to their practice squad in October 2016 before releasing him in March.
ESPN's Mike Rodak contributed to this report.