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.