San Francisco’s preseason opener vs. Denver yielded a 30-9 setback, but the real headlines were the cluster of injuries and how quickly the 49ers’ depth will be tested. Key youngsters exited (Bethune, Sigle, Abdullah, Beal Jr.) with a mix of ankle, knee, rib, and groin issues, while Western Kentucky rookie Upton Stout and Mykel Williams joined the casualty list. Coach Kyle Shanahan emphasized cautious handling, with timelines pegged to next week’s joint practice against the Raiders. San Francisco hopes several returning players (Cowing, Renardo Green) clear workouts soon to rejoin practices. The situation will shape practice reps and potential Week 1 depth, especially at linebacker, safety and edge. Fans will be watching how quickly the squad recovers and who steps up in the interim.