What happened: San Francisco moved to 2-0 with a 35-13 Week 2 win over Miami on Sept. 20, with Demarcus Robinson exiting with 6:46 left in the second quarter. He went down after a 20-yard reception from Brock Purdy and was carted off without returning. Kyle Shanahan said Monday the injury is a high ankle sprain with a 3-6 week absence likely requiring injured reserve.

Why it matters: The absence tests San Francisco's receiver depth during an unbeaten start. Losing a veteran target limits rotation as the 49ers manage early-season injuries.

What to watch: Watch for an injured-reserve move this week and how San Francisco reshuffles receiver reps.