Mexico's hopes of upsetting Brazil in the Olympic men's final on Saturday have suffered a major blow after Tottenham striker Giovani dos Santos was ruled out with a muscle injury.
Dos Santos missed the second half of Mexico's semi-final win over Japan on Monday after suffering the problem and has been unable to recover for the gold medal showdown at Wembley.
"Giovani will not be able to play," Mexico coach Luis Fernando Tena confirmed on Friday. "The injury is not that serious but it does not allow him to play.
"He is sad, he had dreams of playing in this game. His injury will take two weeks to heal.
"On Monday he will show up at his club and start his rehabilitation."
Dos Santos had scored three times for Mexico during their run to a first Olympic men's final and Tena conceded the forward was devastated by the news.
"He is at his best right now and nobody saw the injury coming," Tena said.
It is painful for him and the players but we are a strong team and can easily overcome adversity."
Tena does at least have several options to replace dos Santos, with Miguel Ponce, Javier Cortes, Raul Jimenez and Hector Herrera all in contention.
Brazil coach Mano Menezes insists there is no chance his players will underestimate Mexico as the five-time world champions look to win a first Olympic gold in the men's final at Wembley on Saturday.
While Brazil have graced the World Cup with some of the best players and most dazzling performances ever seen on football's grandest stage, the Selecao have never managed to replicate those golden moments at the Games.
Brazil were bronze medallists in 2008 but this weekend's showdown with Mexico will be their first Olympic final since 1988 in Seoul, when a team led by Romario and Bebeto finished with the silver.
The South Americans also won the silver in the 1984 Games in Los Angeles, but the failure to bring home a gold has rankled with such a proud football nation for decades.
Brazil's Olympic angst has increased since Argentina won gold in Beijing four years ago and the prospect of taking the top prize previously held by their arch rivals, who failed to qualify for the London Games, has only increased the motivation in Menezes's squad.
Brazil are unbeaten in their five matches, scoring three times in each game to take their tally to 15 goals en route to the final.
The pick of the bunch have been Chelsea's new playmaker Oscar, Santos striker Neymar and Internacional forward Leandro Damiao, who struck twice in the semi-final win over South Korea.
The Gold medal match is due to kick-off at 3pm at Wembley Stadium.
South Korea's men beat fierce Asian rivals Japan 2-0 in the play-off for bronze on friday to claim the country's first ever Olympic football medal.
Japan were bidding to emulate the Japanese team of 1968, who won bronze at the Mexico Games, but despite enjoying more possession, the Asian champions were twice unpicked by their opponents' clinical counter-attacks.
Arsenal striker Park Chu-Young and captain Koo Ja-Cheol scored either side of half-time, as the Taeguk Warriors claimed a measure of revenge for the senior side's penalty shoot-out loss to Japan at last year's Asian Cup.
South Korea's government had promised to spare the players military service if they won the bronze medal and the final whistle sparked wild celebrations from the victors, while Japan's players slumped to the turf in despair.