I thought Real Madrid was a soccer team...
Anyways, this must be bogus. If a Spanish team were to be considered, why not Unicaja, Tau Ceramica or Akasvayu Girona, which are more competitive.
Or other Eurpoean teams, like CSKA Moscow.
IMO, if you'll ever see another foreign team besides the Canadians in the NBA, it'll most probably be a team from the Americas (Mexico, Argentina or Puerto Rico).
What the rumor probably really refers to are exhibition games, like the ones Maccabi Tel Aviv have played with the Raptors.