Mexico will need to explore its attacking depth if it's going to progress at the Olympics, with the America forward and Pachuca midfielder headed home.

Mexico's hopes of repeating as the gold medalists at the Olympics took a blow Sunday, with forward Oribe Peralta and midfielder Rodolfo Pizarro set to return to Mexico because of injuries.

Forward Carlos Fierro and fullback Raul "Dedos" Lopez will be called up as injury replacements, according to Record.

Pizarro had to come off in the 35th minute of Sunday's 5-1 win over Fiji, the team's second group match, because of an injury now diagnosed as a broken fibula. The 22-year-old Pachuca midfielder will leave Brazil and return home for treatement. He'll miss the majority of the remiaining portion of the Apertura campaign.

He scored the second goal in Mexico's tournament-opening draw with Germany.

Forward Oribe Peralta, who also scored in Mexico's match against Germany and assisted two goals in Sunday's victory, played the full 90 despite taking a knock in the 28th minute when he and Fiji goalkeeper Simione Tamanisau clashed heads. Peralta has a fractured nasal septum from the coming together and, after saying he was still under evaluation early Sunday evening, the Federacion Mexicana de Futbol (Mexico's FA) confirmed Sunday night that he is out as well.

"The news about Pizzaro and Oribe, after their respective examinations, is unexpected and said," Mexico U-23 coach Raul Gutierrez tweeted. "We'll analyze the best solutions."

Mexico's final group game comes Wednesday against South Korea, which tops Group C thanks to a better goal difference than Mexico. Both teams have four points. Third-place Germany has two but closes out group play against Fiji. The top two teams from each group advance to the quarterfinal stage.