Spain coach Luis de la Fuente called up Barcelona's 17-year-old defender Pau Cubarsi on Wednesday to replace Pau Torres for the Nations League matches against Denmark and Switzerland.
Aston Villa centre-back Torres arrived at Spain's Las Rozas training base with some "muscular discomfort" according to the Spanish football federation.
Cubarsi is already a key player for La Liga leaders Barcelona but has made only four appearances for Spain and was not part of the Euro 2024 winning squad.
Spain, already through to the last eight, face Denmark in Copenhagen on Friday and then host Switzerland on Monday.