Both players went to the Ballon d'Or as Kopa nominees, with Yamal winning the trophy on the night.
Cubarsi said: "It went very well. I went with my father and my sister and they also enjoyed it. I am very happy. It is a new environment, for me and for my family and friends. Impressive. I don't get nervous, I get along very well. I am a very calm boy.
"Now everyone sees what Lamine is. I have seen it for many years and I know how it is.
"He has no ceiling. It is on a spectacular level. It's fucking stopping Lamine, you don't know where it will come from. An extreme that has this confidence gives us life."
On coach Hansi Flick, Cubarsi also told RAC1: "It seems that we have made some transformation, but we have not changed players. We have made a change of mentality, saying that we are Barça and we have to win. Flick, and also Xavi, gave us opportunities from La Masía and we are very grateful.
"There are still talents to flourish. He is a very close coach. "