Dorlus (groin) has been ruled out ahead of Sunday's game against the Seahawks, Tori McElhaney of the Falcons' official site reports.
Dorlus has played through an oblique issue the last few weeks, but he was unable to practice all week with the groin injury. He'll be forced to miss his first game of the season and will leave a void in Atlanta's pass rush after logging 4.5 sacks across his last five games.