Arribas trained with Ronaldo when a youngster with Real Madrid and is thrilled to see Al-Nassr be part of the Segunda Division club's investment.
He said of training with Ronaldo: "It was precisely the first training session I had with the first team when I was in the Under-18 B team in 2017, and Cristiano was there. The truth is, the news was a bombshell for the city, for us, and for the club.
"We had no idea; I don't know what the impact will be, but I'm sure it will be positive for Almería. I haven't spoken to him. It's true that in these friendly matches we played against Al-Nassr, I had the opportunity to talk to him.
"Also, Fernando Hierro was the sporting director in my first year, and I had a closer relationship with him at Real Madrid, and I met both of them. In the last friendly we played, I did greet Cristiano, and we chatted for a bit."
Arribas also said: "We found out because the manager told us one day when we were watching video footage of the opponent, and he came to us with the news that Cristiano had bought 25% of the club.
"Throughout his career, Cristiano's ambition has been evident, and seeing the project Almería has, he's come here because he understands how much the club can grow here, perhaps in five or ten years. These will be years with him in charge, years in which this club can grow a lot."