According to Variety, Copley was forced to depart the film due to scheduling conflicts with press obligations for The A-Team.
Olyphant will shoot his part in the movie during a break from his FX series Justified.
D.J. Caruso is directing the film, about a group of aliens who escape their worn-torn planet to live on Earth.
Michael Bay is producing the picture, which also stars Teresa Palmer, Alex Pettyfer and Dianna Agron.