La Real were beaten 2-1 at home, with the match marred by crowd trouble.
Oyarzabal later called on UEFA to take action against visiting ultras.
The match:
"I think everything has been overshadowed by what happened, which I think is what we have to give priority to. It cannot happen that people who come to our house to watch the game have to do so in fear or have to leave, because four idiots dedicate themselves to throwing things."
Oyarzabal was clear about who was responsible:
"I think it's important that UEFA didn't take action when I think they needed to be taken. On the bench we started to see that people in the corner of the family stand were starting to raise their arms and run, and we saw upstairs that they had broken the glass and were sneaking in to throw things down. I think everyone was aware of what was happening, we told the field steward to speak to the president to stop the game, but nobody did anything."
Oyarzabal insisted on his complaint:
"Today's message is to UEFA, that they should realise that things like this cannot happen, that this damages the image of football today, and theirs, because they could be the main culprits for the fact that it has not been stopped at the time."
The 10 also spoke about the referee:
"I don't know whether to suspend the game or to get involved, but there should have been a moment of pause, for the referee to blow the whistle and for us to focus on what we had to focus on, because everyone had one eye on what was happening in the stands. The priority or focus was not the football, but stopping what was happening in the stands."
Oyarzabal has already made a request for the future:
"I think that from the first minute, knowing who was coming, measures should have been taken and not waiting for things to happen. It is of no use to me that tomorrow there is a sanction and they are not allowed to enter a football ground, because those who have been harmed today have been my fans. You cannot come to a football match to be an idiot and, before that, UEFA should control ticket sales."