River Plate coach Marcelo Gallardo has labelled the decision to move the second leg of the Copa Libertadores final to Madrid "absurd".
The clash is scheduled to be played at the Santiago Bernabeu on Sunday, pending the outcome of respective appeals by each club.
River issued a statement last week saying they reject the decision to move the second leg, which is poised at 2-2 after the first leg at La Bombonera, away from Argentina. The game was initially due to be held at their own El Monumental stadium but was postponed after an attack on the Boca team bus by a group of fans.
Boca, meanwhile, want River disqualified for the bus incident and have threatened to take their case to the Court of Arbitration for Sport (CAS) if CONMEBOL does not declare them champions.
Speaking after a 3-1 win over Gimnasia La Plata, Gallardo was critical of the plans to move the second leg to Spain.
"They made a decision, no matter how absurd it is, they made a choice. What do you expect from me? I cannot answer all that I think and feel now," he said.
"I will not do it because we need to focus on what is next now, and this is to get ready for this game in the best way possible so we can defend our supporters in the best way we can.
"We are the only ones who can defend our supporters, inside the pitch, next Sunday. No one else will."
Gallardo feels the 2018 final will be looked back on as a "totally shameful event", adding he feels River's fans had been robbed.
"The Copa Libertadores de America, being played 10,000 kilometres away from home. Someday, we will rethink all that is happening now, and maybe we will remember this as a totally shameful event," he said.
"We cannot do anything because we have to play this match, but our supporters were robbed. Our fans have been robbed of this chance.
"They robbed River's fans, tomorrow maybe it could be another team, no matter which one."