What happened: Darnold left Seattle's opener after the first drive with a glute injury, and Drew Lock finished the win over New England by going 16 of 22 for 187 yards and a touchdown. Lock is now lined up to start against Arizona, with Jalen Milroe set to back him up.

Why it matters: Keeping Darnold off injured reserve preserves the chance of a relatively quick return instead of a mandatory four-game absence. Seattle already had to finish its opener without Sam Darnold, and ESPN reported a return around Week 5 is possible if the rehab stays on track.

What to watch: Daily rehab updates and next week's practice work will be the key markers for Darnold's availability beyond Sunday. Seattle's Week 2 plan should also clarify how much of the emergency role Milroe would carry behind Lock.