Karlos Williams, who was cut by the Buffalo Bills 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, according to a league source.

Williams already had one game left on a 10-game suspension for violating the NFL's substance-abuse policy.

He is a free agent after being waived by the Pittsburgh Steelers this offseason.

David Irving of the Dallas Cowboys has been suspended four games for a performance enhancing drug violation.

Irving started two of 16 games for the Cowboys in 2016 and had four sacks.

Irving signed his exclusive free-agent tender earlier in the offseason and is set to become a restricted free agent after the 2017 season. 

Justin Gilbert has been suspended without pay for at least one year for violating the NFL's substance abuse policy.

Gilbert received a four-game suspension from the NFL in May after testing positive for substance abuse, according to Schefter.

Gilbert was the eighth overall pick of the 2014 draft by the Browns. Cleveland traded him to the Steelers before the 2016 regular season and played sparingly before being released in February.