It's only June 15 and the Dallas Cowboys have already suffered their first major loss of the 2018 NFL season. It's a loss that'll feel awfully familiar. 

According to NFL Network's Ian Rapoport, Cowboys defensive lineman David Irving has been suspended four games for violating the league's substances of abuse policy. So, Irving will miss the Cowboys' games against the Panthers (away), Giants (home), Seahawks (away), and Lions (home). He'll be eligible to return in time for their game against the Texans (away) on Oct. 7.

This should sound familiar. Last summer, Irving got suspended four games for violating the league's performance-enhancing drugs policy. So, this will be the second straight season that Irving misses the first four games of the season. It's a significant loss for the Cowboys, who have been ravaged by suspensions over the past few seasons. 

The tweet below was sent out when Irving was suspended last year. It does not include Ezekiel Elliott's six-game suspension last season or Irving's latest ban.

It's a brutal loss for the Cowboys. Irving might not be a superstar the way defensive end DeMarcus Lawrence is, but he's one of the most important starters on a defense that finished 25th in DVOA a year ago. This is a Cowboys defense that can't afford to be without their most important players, but that's the reality they face heading into the new season.

In an eight-game campaign in 2017, Irving collected a career-high seven sacks and graded out as Pro Football Focus' 28th-best interior defender. In 2016, Irving broke out with four sacks, which was a career-best at the time. His 11 sacks since 2016 rank second on the Cowboys behind only Lawrence's 15.5.

Irving's absence will place more pressure on defensive linemen like Lawrence, Kony Ealy, Maliek Collins, Jihad Ward, Tyrone Crawford, and Taco Charlton. Luckily, the group is led by defensive coordinator Rod Marinelli, who is best known for his ability to get the most out of his defensive lines. It's time, once again, for Marinelli to coach up the unit so that they can survive without one of their most integral pieces. 

According to ESPN's Todd Archer, Irving will lose out on roughly $685,000 of his $2.91 million salary a year after losing $150,000 due to his previous suspension. Irving, 24, is scheduled to become an unrestricted free agent after the season.