It may just be the world's most intimidating stadium: Azteca -- located in the heart of Mexico City. A place where the punishing heat, choking smog and high altitude destroy the opposition.
The World Cup will be played half a world away but, for Mexico, which opens the tournament Friday against the host South Africans, its home stadium provides the best training ground possible for this World Cup.
Seven of the 10 stadia in South Africa are at altitude. All of Mexico's group-stage matches will be held at 1,310 metres above sea level -- or higher.
Mexico has a tradition of being brilliant at home, and brutal on the road. But this isn't a normal road trip. The rarefied air will seem homey to most of the Mexicans. For the first game, South Africa's home advantage won't be completely nullified, but it won't be as great as one might think.
Coach Javier Aguirre decided to bring an extremely young team to South Africa. The core of this team is the same as the one that played at the 2007 under-20 World Cup in Canada. That team made it to the quarterfinals, where it lost to Argentina, the eventual champs. Before the draw forced the Mexicans to crash into Argentina, they had breezed through the opposition.
Midfielders Pablo Barrera, Efrain Juarez and Giovani dos Santos came from that squad.
"El Tri" also will depend on 2007 U20 grads Carlos Vela, a 21-year-old who can't break into Arsenal's starting lineup, and Javier Hernandez, the 22-year-old who is Manchester United's star off-season acquisition, to provide the goals. Hernandez scored at BMO Field in a win over Gambia back in 2007.
Dos Santos, on loan to Turkish giants Galatasaray, was the team's top scorer in Canada.
Juarez, 22 has the edge to take the spot on the right wing. That would leave out winger Andres Guardado, former Deportivo La Coruna teammate of Toronto FC's Julian de Guzman.
Maybe Guardado is too old for Aguirre. After all, he's 23. That's ancient on this team.
You can look at Mexico's team as being either inexperienced at the senior level, or a team with so many young legs that will be better at handling the conditions than some of the other teams in the group, namely France, which features a large group of players on the wrong side of 30.
When France and Mexico play at altitude, whose legs will last late in the second half?
Mexico just came off a 2-1 win over Italy in a friendly. The young Mexicans ran the hell out of the older Italian squad. And that game was in Belgium.
Yes, Mexico struggled early in CONCACAF qualifying under the conservative reign of coach Sven-Goran Eriksson, who wanted the team to be far more cautious than it has traditionally been. After Eriksson was canned, Mexico lost just one of six qualifying games under Aguirre, as he believes in a 4-3-3 system that's all about attack, attack, attack.
The joy came back to Mexican soccer. The young players were allowed to play without leashes.
The altitude won't only affect the players' lungs and legs, it will also affect the flight of the ball.
Altitude can add 5% on to the speed and distance of shots, but it will also reduce the players' ability to bend the ball on free kicks and corners.
That may not seem like a lot, but it can make the difference between a corner kick meeting the head of an attacker or soaring over the heads of the players in the penalty area.