Cowboys defensive end Randy Gregory had his drug policy-related suspension lengthened from four games to 14 Tuesday, the NFL announced.

Sources said earlier this month that the NFL Players Association had withdrawn an appeal of Gregory's suspension.

Gregory was already serving a four-game suspension for violating the league's substance abuse policy. The new suspension, which is for 10 games, is tacked onto that total. That means the earliest Gregory could return to practice would be Dec. 19, making him eligible for the final two games of the regular season.

Gregory checked himself into a treatment center this summer intending to complete the program before the Cowboys reported to training camp on July 28, sources said. But a source said that Gregory left the facility for a weekend and missed a scheduled test.

A missed test carries the same weight as a failed test.

Gregory was placed on the reserve/did not report list and did not take part in training camp.

The Cowboys recently removed the defensive end from that so he could report to the team's new practice facility and be around his teammates.

Gregory tested positive for marijuana in February 2015 at the NFL scouting combine and entered the league in the first stage of its substance abuse program. That's the reason he slid to the Cowboys in the second round of the draft. He tested positive for marijuana twice at Nebraska, in January and April of '14, and was told he would be kicked off the team if he failed a third time.

The suspension means he has failed/missed at least four tests while a member of the Cowboys.

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