Boca Juniors asked doctors to examine their players minutes before their Copa Libertadores final against arch-rivals River Plate on Saturday after tear gas fired by police at River fans drifted into the Boca team bus, local media reported.
Several of the Boca Junior players are said to have been badly affected by the tear gas, with Boca Secretary General Christian Gribauldo saying also that some have been cut by glass from the smashed windows, and that they are not in "any condition to play".
"They're forcing us to play this game under these conditions where we have teammates who are not well", Tevez told reporters outside the locker rooms.
After initially appearing to postpone the match, Conmebol eventually made a decision to call off the game until Sunday - 5pm local time, 8pm in the UK.
The first leg ended 2-2 at River Plate after awful conditions saw the game postponed for 24 hours.
But a statement released by CONMEBOL this evening says the clash has been postponed and will be played at 7.30pm local time, rather than suspended until further notice.
The Superclasico is regarded as one of the football world's greatest rivalries, not just for the play on the pitch (if that even eventuates) but for the potentially chaotic passion of its fans - fully on display when Boca supporters packed out their home stadium simply to witness its players in training before the big final.
A riot policeman fires his gun after the match was postponed
"I would have loved to have played this game", Juan Roman Riquelme reminisced as he reflected on the tie.
Footage also emerged of the Boca bus approaching the stadium at high speed, trying to avoid the barrage from the River Plate fans.
Despite being taken to hospital for treatment, the player was named in the provisional starting lineup and medical services confirmed there were no medical grounds on which the match could be called off.
But when the police escort, surprisingly according to locals, led the Boca bus on to Avenida Monroe a little after 4pm, it was surrounded by River fans who pelted it with missiles.
The Boca president, Daniel Angelici, said: "We've had stones thrown at us before". It completely surprised me. We don't have a leg to stand on: if we have to play, we are going to play.
The showdown will now take place from 9pm GMT after River Plate fans caused chaos in Argentina.
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