"I haven't made my final decision yet because I want to be as fair as possible," Aragones was quoted as saying in sports daily AS on Friday.
Earlier this week Aragones held a World Cup get-together with a squad of 27. He appears to have settled for four strikers -- Valencia's David Villa, Atletico Madrid's Fernando Torres, Real Madrid's Raul and Liverpool's Fernando Morientes.
Villa has scored 24 goals in the Primera Liga this season. Captain Raul has been struggling for form since returning from a knee injury in February.
There remain doubts in midfield. Valencia winger Vicente played his first game after recovering from an ankle injury last
Barcelona's Xavi has had limited match practice since recovering from his knee injury but his playmaking may be preferred over Valencia's Ruben Baraja.
Recent Spain recruits Arsenal's Cesc Fabregas, Villarreal's Marcos Senna, and Barca's Andres Iniesta will probably make the cut after impressing for their clubs in the Champions League.
In defence the debate has focused on the left back position being fought over by Chelsea's Asier del Horno, Deportivo Coruna's Joan Capdevila and Atletico's Antonio Lopez, now that Getafe's Mariano Pernia looks set to miss out.
Valencia defender Carlos Marchena could be left behind because he has not played regularly for his club, along with Villarreal right back Javi Venta who has yet to win a cap.
Spain are likely to take three goalkeepers - Real's Iker Casillas, Liverpool's Pepe Reina, and Valencia's Santiago Canizares although Barcelona's Victor Valdes could still be in the reckoning.