GREEN BAY, WI - OCTOBER 16: David Irving #95 of the Dallas Cowboys celebrates with his team against the Green Bay Packers during the third quarter at Lambeau Field on October 16, 2016 in Green Bay, Wisconsin. The Dallas Cowboys defeated the Green Bay Packers 30-16. (Photo by Hannah Foslien/Getty Images)

The Cowboys are officially losing one of their best defenders to suspension

This really hurts.

The Dallas Cowboys will have some depth concerns on the defensive line for the first four weeks of the season.

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The NFL announced on Wednesday that defensive end David Irving will be suspended for four games for violating the league's performance-enhancing drug policy, according to Pro Football Talk.

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NFL Network reporter Ian Rapoport reported in May that Irving was facing a suspension, and he said it stemmed from a supplement Irving was taking for which he had a marketing deal.

Irving is expected to appeal the suspension.

Irving can participate in preseason games and practices, and his suspension will take effect during the week before the Cowboys' season opener.

He will be eligible to return on Oct. 1 before the Cowboys play the Los Angeles Rams.

Irving recorded four sacks and forced four fumbles last season for Dallas. The Cowboys will turn to rookie Taco Charlton to fill the void during Irving's four-game suspension.

(h/t Pro Football Talk)