Javi Martinez and Raul Albiol make up Spain's central defence in an experimental starting line-up for the friendly against Panama.
Bayern Munich man Martinez, though not unused to playing as a centre back, is a midfielder by trade.
Other fringe players making rare starts at the Estadio Rommel Fernandez are Barcelona goalkeeper Victor Valdes, Atletico Madrid fullback Juanfran and Real Betis regista Benat Extaberria.
David Villa wears the captains armband and starts up front alongside Pedro Rodriguez and Juan Mata – a controversial exclusion from Vicente del Bosque's recent squads.
The game kicks off at 9.30 GMT.
Starting line up:
Spain: Valdes; Juanfran, Albiol, Javi Martinez, Alba; Busquets, Benat, Iniesta; Mata, Villa, Pedro
Think you know your Spanish football? Share your knowledge, tips and comments to win cash prizes in OLBG's World Cup tipster competition - £10,000 to be won!