With the best generation of footballers at their disposal, the Spaniards are heavy contenders to win the Olympic gold at the London Games.
Despite several injury concerns to Barcelona playmaker Thiago Alcantara and Athletic Bilbao winger Iker Munian, coach Luis Milla has the option of some fine talent like Juan Mata, Christian Tello, Alberto Botia, Ander Herrera and Adrian Lopez.
After a second place finish at the 2000 Olympics, Spain failed to qualify for the past two Olympics. But with this group of young talent, La Roja aim to finish at the top.
Japan have surprisingly left out Manchester United midfielder Shinji Kagawa and Keisuke Honda, who are now Japan's most popular players.
Coach Takashi Sekizuka will heavily rely on his defenders to wave off the Reds attack. As expected, Spain will dominate in possession while Japan have their main strengths in defence. Defender Hiroki Sakai will lead the back line as Shuichi Gonda will be the stopper for Japan.
Spain: De Gea-Alba, Montoya, Botia, Alvaro-Martinez, Isco, Koke-Mata, Adrian, Rodrigo
Japan: Gonda-Tokunaga, Sakai, Yoshida, Suzuki-Ohgihara, Usami, Kiyotake, Higashi-Nagai, Otsu