According to The Washington Post, Juventus announced the cancellation of its North American tour, so the friendly match Real Madrid was going to play against the Italian squad on August 5 has been cancelled. This friendly was as part of the 'World Football Challenge', a competition that aims to promote football in the U.S.A.. Real Madrid won the tournament last year.
Despite the cancellation, it is expected that the tournament organizer is able to find another rival for Real Madrid in order to play a friendly match on the same date and in the same place (Las Vegas). The other Italian club matches on North American soil were a friendly against DC United in Washington and other match against Paris Saint-Germain in Montreal.
Link: Real Madrid Pre-season 2012-2013