Luis spoke to Tiempo de Juego on COPE after Brazil's 5-0 win over Peru on Saturday.
He said, "I have no idea if Neymar's going to Barcelona because I haven't spoken with him, but if it happens it would be a huge shock to the transfer market. I would like to see him back at Barca.
"He was happy there, he enjoys himself much more there and he needs to get his smile back and that joy that he had. I know he would be happier back at Barcelona but I am not with him and I don't know what he's thinking. I just know what I read in the press."