Before his two-goal salvo in Bournemouth's 4-2 defeat, Semenyo reported being racially abused by on Liverpool supporter on 29 minutes.
Referee Anthony Taylor halted the game and spoke to both managers and also both captains before resuming.
Afterwards, Iraola told the Daily Echo: "I didn't notice live because a lot of people were shouting.
“But straight away, Antoine and the ref both explained the situation to both managers. To be fair, I think from the Liverpool side they have identified this person.
“It's a shame that in the first game of the Premier League, a very good game of football between two teams that are fighting for their side, but playing a really good game.
“We have to start talking about things that probably we considered already from the past. But obviously they are not from the past.
“We have to continue reinforcing the messages. And it's a big shame. It's a big shame because the end most of the news will be about this thing. And they have to be about the thing because obviously something that still is a big problem, not just in football, but overall and also in football.
“We should be talking about what a good game it has been. Two teams playing well in the first game of the season. And probably we'll be talking about other things.”
A big shame
Asked for an update on Semenyo, Iraola said: “In the heat of the moment I think Antoine understood the situation.
“He was calm. He continued playing, for sure he has been, the head works in the next minutes. But we asked him, he was fine to continue. He looked composed.
“But it's true that now at the end of the game he was still, for sure he will be, not on purpose, but the head always goes to these things and for sure he's asking why it still is happening today and it's a big shame.”