Viktor Korchnoi
The match was to be held in Pasadena, California, but the Soviet Chess Federation protested. Possibly this was because Korchnoi was a defector and the match was in the cold-war enemy's backyard, and because of the soon-to-be-announced Soviet decision to boycott the 1984 Olympic Games in Los Angeles). At any rate, Kasparov was not allowed to fly there to play the match. This defaulted the match to Korchnoi.