Sánchez/Uśtero should control this matchup through superior left–right balance, heavier volley patterns, and better decision-making under pressure. Merino/Manquillo can compete if they win the first exchanges and keep points fast, but over a full match Ariana’s control and Ustero’s finishing should tilt rallies. Prediction: Sánchez/Ustero in straight sets unless Merino/Manquillo dominate early return games.