It's been a rough week for the Cowboys' defensive line.

The NFL on Friday announced that David Irving is suspended indefinitely for violating the league's substance abuse policy.

That followed the news from earlier in the week, when defensive end Randy Gregory was suspended for the same violation.

For Irving, it's not his first drug-related suspension: He was suspended for the first four games of both the 2017 and 2018 seasons for violating the league drug policy. A third violation typically results in a year-long ban.

In January, sources told WFAA that Irving had missed multiple drug tests, but his agent refuted those claims.

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RELATED: Reports: Randy Gregory suspended indefinitely for violating drug policy

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As for Gregory, his violation announced this week was his fourth infraction since he was drafted by the Cowboys in 2016. Gregory was suspended for most of the 2016 season and all of 2017 for previous drug violations.