In the early rhythms of a new season, young talent and fragility arrived together on a Las Vegas practice field, as Raiders rookie Ashton Jeanty — the sixth overall pick and the cornerstone of a rebuilding franchise's hopes — was helped off the field Sunday with a right ankle sprain. The injury, reported by ESPN's Adam Schefter, is not expected to be a long-term absence, though its precise severity remains unresolved. For a team and a new coach building an offense around one player's promise, the episode is a reminder that the architecture of ambition is always one misstep from uncertainty.