Ruiz/Rubio should enter as the more stable pairing in a FIP Silver setting, with a higher floor in side-out patterns and transition defense. Gil/Castaño can compete if they speed up exchanges and force uncomfortable backhand-lane decisions, but over a full match Ruiz/Rubio’s consistency and net control should tilt it. Prediction: Ruiz/Rubio in 2 tight sets, with one swingy tiebreak scenario possible.