Boca Juniors players have been injured after their bus was attacked on the way to the Copa Libertadores final against River Plate on Saturday.
TV footage shows a window in Boca's bus being smashed apparently by a tear gas grenade upon arrival at River Plate's Monumental de Nunez Stadium.
Todo Noticias news channel says six Boca players have been affected and two have already been ruled out for the second leg of the final. Striker Carlos Tevez is one of the players affected by the incident.
Boca chairman Daniel Angelici has requested the second leg be suspended, but no response has been given yet by South American soccer body CONMEBOL.
Boca and River drew 2-2 in the first leg two weeks ago.
The incident occurred three years after a Copa Libertadores last-16 tie between the same teams was abandoned at halftime after Boca fans attacked the River players with pepper spray in the tunnel.
River were given a bye into the quarter-finals and Boca were kicked out the competition.
