David Irving might not be on the field with his teammates when the Cowboys open up the 2017 season. As first reported by Mike Fisher of 105.3 The Fan, a CBS Sports Radio station, Irving is facing a four-game suspension for violating the NFL's performance-enhancing drugs policy.

The news was confirmed by ESPN's Todd Archer and Adam Schefter, who reported that "the issue stems from an over-the-counter substance Irving used in an attempt to endorse the product." Fisher wrote that the result of the test isn't "official" yet.

Irving has already filed his appeal of the suspension, according to Archer and Schefter.

So, make that another offseason in which the Cowboys have been forced to deal with suspensions on the defensive side of the ball. Last year, DeMarcus Lawrence, Rolando McClain, and Randy Gregory were all suspended. This year, Irving is the second Cowboy to get hit with a suspension. Gregory will miss the entire year.

This is nuts:

Obviously, Irving's suspension is not good news for the Cowboys. A year ago, Irving registered just four sacks, but three of those came in a two-game stretch late in the regular season. Losing Irving isn't a devastating blow, but given the Cowboys' weakness is their defense, it's still a blow nonetheless. It's also not good news for Irving, who is scheduled to become a restricted free agent after the upcoming season.

The Cowboys can take solace in the fact that they focused on bolstering their defense in the draft, so they have a bit more depth on that side of the ball than they did last year. First-round defensive end Taco Charlton should help fill Irving's void if his appeal falls short of its goal.