What happened: Ed McCaffrey's Broncos legacy and Christian McCaffrey's 49ers role give this meeting a built-in family thread. The buildup also reaches beyond lineage, touching Christian McCaffrey's Colorado high school résumé and Hall of Fame case.

Why it matters: That adds another layer to a game where the Broncos are measuring themselves against an unbeaten San Francisco roster. It also connects one of Denver's past stars to one of the 49ers' central pieces in the current season.

What to watch: Game-week availability reports and Denver's defensive plan will show how much of the matchup runs through McCaffrey. San Francisco's push to keep its unbeaten start intact raises the stakes around the visit.