What happened: Darnold has not practiced since suffering a glute injury in Seattle's season-opening win over New England. Drew Lock is set to start Sunday against Arizona, with Jalen Milroe serving as the backup. Seattle also expects to be without Ty Okada, while Nick Emmanwori and Anthony Bradford are listed as questionable.
Why it matters: The injury forces Seattle into an early quarterback shuffle for an NFC West game and leaves open how long its Week 1 starter will be sidelined. Any extended absence would keep Lock and Milroe at the top of the depth chart after the Seahawks ruled Darnold out for Sunday's Cardinals game.
What to watch: Seattle's next practice availability will set the earliest window for Darnold to return. Sunday's result should also show how steady the offense looks with Lock taking the snaps.