The Boca players made it to the stadium and mobile-phone footage showed them woozy, unable to stand and reportedly vomiting after the attack. Some were photographed with their eyes bandaged.

The game was postponed for 24 hours. The mayor of Buenos Aires, Horacio Rodriguez Larreta, blamed the attack on the Barra Brava, the fanatical ultras of the River support.

Then, on Nov. 25, the game was postponed again three hours before kickoff. Now, the South American soccer body has announced that the second leg will take place on Dec. 8 or 9—but outside the country. It has not announced any more details.

Perhaps we could have seen this coming, with an unprecedented meeting in one of world soccer’s fiercest rivalries taking place under high-pressure conditions. Neither set of fans could bear the shame of losing. The omens were never good.

In 2015, a last-16 Copa Libertadores match between River and Boca had to be abandoned at halftime after Boca fans attacked the River players. Players and the managers are regularly escorted on and off the pitch by police in riot gear when they meet.

Forcing an Argentine showpiece to moved out of the country is another thing altogether. The biggest club match in the 127-year history of Argentine soccer has turned into its most shameful episode.

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