Who was Apollo Creed's originally scheduled opponent before Rocky in the first film?

Apollo Creed was originally scheduled to fight Mac Lee Green before Rocky became his replacement opponent.

In the film’s setup, Creed is preparing for a major title bout tied to the United States Bicentennial. Green, described as a leading contender, injures his hand about five weeks before the scheduled fight and cannot compete. With other potential challengers unavailable or unable to prepare in time, Creed’s camp looks for an alternative.

Creed then chooses Rocky Balboa, a little-known Philadelphia club fighter nicknamed the Italian Stallion. The decision is presented partly as a publicity opportunity: Creed believes an unknown local boxer will create a memorable spectacle while allowing him to keep the heavily promoted Philadelphia event.

Mac Lee Green is easy to miss because he never appears as an active opponent in the movie. Names such as Spider Rico and Joe Czak are associated with Rocky’s boxing world, but neither was the originally scheduled challenger for Creed’s title defense. Green’s injury is the story trigger that creates Rocky’s once-in-a-lifetime opportunity.