Castelló/Rufo should enter as the more stable pair in P2 rhythm: stronger first-volley structure and better transition defense typically translate well in Cancún’s faster, lively conditions. Talaván/Saiz can threaten if they speed up with early lobs-to-bandeja sequences and steal net time, but they’ll need a high return level to avoid getting pinned in the backhand corner exchanges. Prediction: Castelló/Rufo in 2, with a tighter second set if Talaván/Saiz win the opening break battle.