Green's first movie roles were in the 1984 films "Billions for Boris" and "The Hotel New Hampshire"; the second film cast him alongside Jodie Foster and Rob Lowe. He appeared in the 1987 film "Can't Buy Me Love", playing Patrick Dempsey's character's little brother, Chuckie Miller. He starred in Woody Allen's "Radio Days" (1987) as Joe (a 1930s–1940s boy based on Allen) and appeared in "Big Business" (1988) and, in the same year, "My Stepmother Is an Alien", which also starred "Buffy the Vampire Slayer" co-star Alyson Hannigan.