His first call-up to the senior national squad came in October 2004, for World Cup qualifiers against Belgium and Lithuania, as a replacement for Juanito who dropped out of the original selection because of injury. Carlos Marchena and Carles Puyol were the centre-back pairing in possession, and Pablo remained on the bench for both games. He made his international debut on 17 November 2004 in a friendly against England in Madrid. He entered the game as a half-time substitute for Marchena, with Spain leading 1–0; with 20 minutes left, he appeared to foul Alan Smith in the act of shooting, but no penalty was awardedhe told "Mundo Atleti" that Smith had thrown himself to the floor once he realised he could not reach the balland Spain had no difficulty retaining their lead. Pablo replaced Iván Helguera, who had previously been a regular selection, in the squad for Spain's next match, a World Cup qualifier at home to San Marino in February 2005, but did not play.