The Brazilian collected the ball on the right touchline, he cut inside, left Lucas Digne standing still as he surged into the box and then he finished into the bottom corner past Emiliano Martinez.
Match report:
The 19-year-old received a standing ovation as he was replaced after 87 minutes.
Asked about Rayan’s performance and goal, Iraola told the Daily Echo: “I think he's still in the process of adaptation and he needs to learn a lot and we need to learn a lot from him.
Rayan's first goal for the club came from a superb solo effort (Image: Richard Crease)
“To see him in different positions, in different scenarios.
“But if he does this process while adding numbers like the other day with the assist, like today with the goal, I think he's a player, if we can provide him spaces and situations to go one against one against the defenders, he will produce a good offensive threat.”
Rayan is a physical winger, standing at over six foot and he is an imposing winger.
Physicality is often something that players moving to the Premier League struggle with.
Rayan (Image: Richard Crease)
On Rayan’s physical attributes, Iraola said: “I think it's one of the things we were trying to improve this market, and still we are in need to improve because we lost Antoine [Semenyo] and Dango [Ouattara], that probably are the most physical players that you can find.
“And we needed someone, I don't know if as strong, but at least to cover a little bit our lack of physicality, to help us even in the aerial duels, in the set plays.
“In that sense, he still needs to play to this rhythm. He finished dead today.
Rayan (Image: Richard Crease)
“He was cramping at the end. That's the reason we took him out. But it's a matter of time.
“He's 19, comes to the best league in the world probably, he is used to playing in a different rhythm. And I don't know if he will be ready in 3 days because today he was dead at the end of the game.”
Iraola added: “I wanted to keep him on because I was seeing that he was being dangerous, but I was feeling even the last 15 minutes he played, he didn't have a lot.
“And it's true, it's good that he has suffered, the same as Alex Jimenez. They were both cramping, but they were playing well and they have given everything.
“At the end, we decided to change both on the right side, but I think positives from him.”