In a Friday morning press conference, Real Madrid unveiled plans for a €400 million stadium redevelopment, which President Florentino Perez expects to be a global symbol (h/t ESPN FC's Dermot Corrigan).

On Sunday, Los Blancos will visit a team who have been settling into their brand-new stadium rather nicely. That team is Athletic Bilbao, whose new San Mames Stadium opened for business in September 2013. Built partially over the site of the old San Mames Stadium—the final stand behind the goal has yet to be completed as the old "Cathedral" was still in the way—the UEFA 5-star arena is filled with 53,000 locals for every home game. 

San Mames is named after Saint Mammes, a Christian who was thrown to the lions by the Romans, but who survived when the beasts refused to eat him. (This is also why Athletic Club are known as "Los Leones.")

Against all odds, the proverbial lion that is Spanish top-flight football has never taken a fatal bite out of the Basque club. 

Along with Madrid and Barcelona, Bilbao are the only club who have never been relegated from the Spanish Primera since its inception in 1929. Incredibly, they have managed to stay competitive in the modern game with a self-imposed handicap: the Cantera.

This policy means they will only sign players originating from or trained in the Basque region. Whereas their La Liga rivals can pick from a global population of billions to fill their starting XI, Bilbao are limited to a relatively small area containing a little over two million people.

While the Cantera has received criticism for its insular nature and limits on transfers, the fans wouldn't have it any other way. In a poll held in the 1990s, 75 percent of Athletic Club supporters said they would rather be relegated than abandon the policy, per Football Cantera.  

When you look at the amount of Spanish national team players they have produced—and the current strength of the team—it's hard to fault the system.

The new San Mames has become a fortress. Bilbao was never an easy place to go for a visiting team, but Ernesto Valverde's side are undefeated in the league on their new turf. They have only dropped four points at home and in December inflicted Barcelona's only league defeat of the season so far. In fact, their only loss at the new venue so far was in the Spanish Cup to Atletico Madrid on Wednesday.

Bilbao's attitudes toward recruitment couldn't be any more different than that of their anxious visitors on Sunday. 

Real Madrid are renowned for their incredible youth setup, but relatively few of their homegrown stars get to shine at the Bernabeu due to a policy of importing megastars that began in the 1990s. In 2013, for example, Transfermarkt shows us that Madrid spent nearly £144 million on players. Athletic Club had a particularly extravagant year, splashing £13.4 million on players of Basque origin.  

Yet despite these different attitudes—and the phenomenal spending power of Los Blancos—Athletic Club find themselves just one place behind Real in fourth. A defeat at San Mames could put Carlo Ancelotti's side four points off the lead in the title race. It really makes you wonder about the merits of "Galacticos." 

Athletic Club aren't in danger of upsetting the Barca-Real-Atletico hegemony in La Liga anytime soon, but it is incredible that they are knocking on the door of Champions League football on the kind of budget that Florentino Perez might find stuffed down the back of his sofa. 

I am lucky enough to have visited Bilbao on several occasions to film a documentary about them. I experienced the unwelcoming atmosphere that the Basques are famous for creating at San Mames a few times and watched them train at their unfussy Lezama training ground. We filmed a small segment on the field at the old San Mames, something the club weren't entirely keen on us doing because they consider it to be "sacred turf."

When you walk around the streets of Bilbao, you do not see kids in Madrid or Barcelona shirts. You certainly don't see them wearing Spain shirts. Everything is red and white stripes.

At the time of writing, bookmaker bwin is giving Real Madrid odds of 1.75 for a win, compared to 4.75 for the home team. Saint Mammes was probably given much longer odds when he was thrown to the lions by the Romans—and look how well his legacy is persevering. 

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