Jamal Adams is actually no longer with the Seahawks — he signed with the Minnesota Vikings in 2026. As for how long he's out: he suffered a severe non-contact right knee injury in preseason Week 1 (August 15, 2026) and is out for the entire 2026 season (from the Jamal Adams page).
Head coach Kevin O'Connell said the initial imaging "didn't look good," and Adams was carted off after just 12 snaps. Given his extensive injury history that dates back to his Seahawks days, there's legitimate concern about the viability of his NFL career going forward.