Here is a look at the key midfielders looking to earn starting jobs in Aragones' 4-1-4-1 (or 4-4-2 if he goes two strikers up top):
XAVI (Barcelona). At 28, the Catalan has been a key player for Barcelona and Spain. Xavi, who joined Barca at the age of 11, plays a simple game, using his dribbling and short passing game to maintain possession. He likes to take free kicks and can score -- he has five goals for Spain.
XABI ALONSO (Liverpool). One of the most successful of the Anfield Spaniards, Xabi Alonso is nevertheless considered something of a question mark in the Spain midfield. After starting against Peru, he could see his spot taken by Marcos Senna or Cesc Fabregas against the USA.
CESC FABREGAS (Arsenal). The 21-year-old Fabregas was named the EPL's Young Player of the Year and a nominee for the Player of the Year, but he could find himself on the sidelines at the start of Euro '08. Arsenal lured him away from Barcelona at the age of 16, and he has been a force in midfielder at Arsenal, where his development under Arsene Wenger has been a reason for the Gunners' continued presence near the top of the EPL.
ANDRES INIESTA (Barcelona). Like Xavi and Fabregas, Iniesta is a product of the Barcelona youth program. He has emerged as a key figure at Barca, starting along with fellow Catalan Xavi in the face of competition from high-priced foreigners. Like Xavi, Iniesta is cool on the ball, though he may be a better distributor.
DAVID SILVA (Valencia). The 22-year-old Silva gives Spain a threat out of midfield from the left wing. Aragones has stuck with him even though Valencia struggled in 2007-08.
MARCOS SENNA (Villarreal). At 31, the Brazilian-born Senna has been a fixture in the Spain squad since before the last World Cup. His play at La Liga runner-up Villarreal this season is an argument in his favor.