First-choice from the start, Astudillo scored four league goals in his first season, and was instrumental in the Basque side's runner-up run in the UEFA Cup the next year.
Astudillo remained loyal to Alavés throughout the vast majority of his Spanish stint, playing in the top flight as well as the Segunda División as they were twice relegated from the former (in 2003–04, he collected a season-worst 19 yellow cards).
However, in January 2008, he rejoined the top tier, signing on loan with CA Osasuna who had lost another central midfielder, Javad Nekounam, severely injured in preseason.
[3] During the season, Astudillo was instrumental in helping the Navarrese barely escape relegation as he scored the game's only goal at RCD Espanyol on 13 April 2008.
[4] In August 2009, after Alavés suffered relegation to the Segunda División B, he bought out the remainder of his contract and returned to his country after ten years, joining Rosario Central;[5] he made a best-ever 346 competitive appearances for his main club.