The second leg of the final at River’s El Monumental stadium was due to get underway at 8pm UK time.
But the match has been delayed by an hour after the Boca coach carrying their players was badly damaged en route to the match.
Football writer for the Independent, Miguel Delaney, tweeted that the bus was attacked by River fans and police used pepper spray to disperse supporters.
He tweeted: “Pepper spray got onto Boca bus after River fans attacked it, and police tried to disperse, leaving players wretching.
“Conmebol meeting now to discuss if game delayed by an hour.
“Boca players apparently want to play, though some visibly wretching coming in.”
Footage from Argentina showed the Boca bus with several of its windows broken.
It was also claimed Boca players were vomiting in the dressing room from the pepper spray with former Manchester United star Carlos Tevez among those affected.
“They attacked us from everywhere,” said Boca captain Pablo Perez.
Defender Carlos Izquierdoz added: “They threw pepper spray, sticks and stones. It came in the bus from everywhere.”
The South American Football Confederation, CONMEBOL, held talks with the clubs and announced the match will start at 6pm local, 9pm UK.
This is the first ever time there has been a Superclasico in the final which is the South American equivalent of the Champions League.
The first meeting ended in a 2-2 draw nearly a fortnight ago after being rescheduled to the Sunday due to torrential rain.
The 70,000-seater stadium would have been full of River supporters after both clubs agreed that no away fans would be allowed to attend either leg of the finals.
About an hour before kick-off and with the Monumental stadium filled to capacity, Boca officials told reporters some of their players were not fit to play in the decisive second leg.
“The players are all hurt, you can’t play this way,” Christian Gribaudo, Boca’s secretary general said in quotes reported by the Clarin website.
Clarin said six players had vomited in the dressing-room after gas drifted into bus windows smashed by River fans outside the stadium.
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.
River Plate vs Boca Juniors Live Stream
BT Sport are providing live coverage of tonight’s match as Argentina’s biggest rivals go head to head in the final of the Copa Libertadores.
The match will be available on BT Sport 2 HD from around 8:45pm.
BT customers will be able to watch the match on the BT Sport app from 7:45pm.
If you are not yet a BT Sport subscriber, the company advise you can be set up on one of their packages within 15 minutes via their website.
FreeSports are also providing live coverage of the match.