River Plate said Saturday they have refused to play the Copa Libertadores final second leg against Boca Juniors in Madrid, casting uncertainty over the December 9 fixture.
The match between the arch-rivals has been moved to Real Madrid's Santiago Bernabeu stadium after it was twice postponed last weekend after River Plate fans attacked the Boca Juniors team bus.
The game is due to be played in the Spanish capital on December 9, but River Plate said they "confirmed their rejection of the change of location."
In a statement on the club's website, River said it was "incomprehensible" that the game had been moved to Spain.
River said the club bore no responsibility for the "faults in the security operation" for the high profile fixture in Buenos Aires.
"It is incomprehensible that the superclásico cannot take place as normal in the same country where a G20 summit is currently taking place," the club added.
World leaders, including US President Donald Trump and Russian leader Vladimir Putin, are attending the G20 summit in Buenos Aires this weekend.
"The club believes this decision demeans the competition, prejudices those who have bought tickets and makes it unfair," River continued.
Several hours before River put out their statement, Boca Juniors said they were going to appeal against the decision to move the match to Madrid to the South American football federation CONMEBOL, and eventually to the Court of Arbitration for Sport (CAS).
Several Boca Juniors players including Pablo Perez needed hospital treatment for injuries caused by shards of glass and others complained about the effects of inhaling teargas in the attack last Saturday.
Boca then refused to play the match and it was postponed 24 hours, only to then be called off indefinitely the next day.
Boca petitioned CONMEBOL to be awarded the trophy, but that was rejected on Thursday.
CONMEBOL, which is headquartered in Paraguay, decided Argentina was in no state to host such an important match and ordered it played elsewhere, with Real president Florentino Perez jumping on the opportunity and offering use of the Bernabeu for free.
FIFA President Gianni Infantino said Saturday that "idiots ruined the party" for everyone at the Copa Libertadores.
"I was here last Saturday," Infantino said at a press conference at the G20 summit.
"It was a sad moment for everyone. It is a football match. It is not a war, not even a battle."
"We have to work to find out who are the people to blame. You have to identify them and get them out (of football)," said Infantino.
"I hope this does not happen any longer," he said. "This story must mark the end of one chapter and the start of a new one."
The FIFA boss believes it is up to CONMEBOL to decide the fate of the final.
They "must take a decision, they know all the factors," he said, adding: "It has to be played, nothing should stop football."
On social media, the Libertadores, the most prestigious club tournament in South America, has been rechristened the "Copa Conquistadores."
But, Infantino insisted that Argentina "does not have to feel ashamed" over the final being moved to Madrid.
"Argentina has to feel energised to change this, to use it for positive change," he said.
Infantino then told AFP the Madrid game would be "a festival of South-American football".
"I'm sad, CONMEBOL had the most difficult job. They suggested Madrid, it's an exceptional situation,in exceptional circumstances.
"No matter what the decision, ideal or not, any would have its critics. We have to make an effort this game is played in a good atmosphere."
In a sign that despite River and Boca's protests the game will go ahead, several Argentine journalists have posted on Twitter details of where the two teams will train in Madrid next week in the run up to the contentious fixture.