Marcelo Bielsa will go down in footballing history as one of the sport's most fascinating and influential minds.
His Uruguay side will face off against Spain this evening, looking to keep their hopes of knockout football alive.
But for a man who, at times, appears awkward and reserved, why is Bielsa known as 'El Loco'?
Why is Marcelo Bielsa known as 'El Loco'?
Bielsa has drawn the attention of football fans around the globe lately for his timid nature during a FIFA photoshoot: keeping his head bowed and refusing, respectfully, to raise it for the camera.
But there was once a time the Uruguay boss chased fans with a hand grenade, and threatened to pull the pin, after a selection of 'ultras' turned up at his house, following a heavy defeat.
This was back in 1992, when Bielsa was manager of Newell's Old Boys, and he had just seen overseen a torrid 6-0 loss.
He opened the door with grenade in hand, as the Old Boys' most radical faithfuls stood in wait.
When they realised that Bielsa was not making an empty threat, he reportedly chased them down the street after they left, and asked them: "Do you still want to talk?" in his pyjamas.
Other fascinating stories of 'El Loco', meaning 'The Crazy Man', include the time he told one of his defenders that he would seriously sever his finger clean off, if it meant victory for the team.
Or another, which comprises of many occurrences: Bielsa was often locked in the toilet by his staff to contain the fits of rage that had become commonplace after defeats.
Former Uruguay international, and football legend, Luis Suarez spoke on his experiences with Bielsa in a recent interview.
“His entire career has been like that,” Suarez said to Mundo Deportivo. “You have to accept him as he is [and] get used to working with him that way.
"Some agree with it, others don't, but there's a reason he's called that," the ex-Barcelona striker continued.
In the years preceding that recent interview, Suarez once implied that Bielsa's cold, even terrifying, approach to the game was going to alienate Uruguay's players.
He declined to go into solid detail back in 2024, stating that El Loco's behaviour "hurt to see" and he wouldn't discuss for "the good of the group."
When the approach pays off, it pays off. In 2023, the greatest player of all time, Lionel Messi, had glowing words for Bielsa.
After Uruguay beat Argentina and Brazil in back-to-back qualifying games for the World Cup, Messi confessed that Bielsa's hand was visible, with La Celeste's intensity proving too much to handle.
Conversely, when the approach doesn't pay off, the discussion around Bielsa becomes far more toxic. With the coach likely to step down after the 2026 World Cup, results here will define his character.
La Celeste have battled to two draws in the tournament, despite being favourites for both clashes.
In dire need of a victory tonight against Spain to secure progression to the next stage, the outcome could decide whether Bielsa is recalled by Uruguayans years from now as a genius, or just 'El Loco.'
