Sharlto Copley has dropped out of the DreamWorks pic “I Am Number Four” and has been replaced by “Justified” star Timothy Olyphant.

Copley, who rose to the top of studio casting lists after starring in breakout hit “District 9,” had to bow out of the D.J. Caruso-helmed film due to scheduling conflicts with his upcoming press obligations for Fox’s “The A-Team.”

Olyphant, who is also on the rise thanks to the critical hit “Justified,” will shoot the film during his hiatus from the FX series.

Story revolves around a group of nine earthbound aliens who escaped their planet just before it was annihilated by a rival species. Hiding out on Earth, disguised as a human teenager, the title character discovers that he is being hunted by the enemy that destroyed his planet. Alfred Gough, Miles Millar and Marti Noxon penned the screenplay.

Olyphant will play Henri, a guardian and mentor to the story’s title character, played by Alex Pettyfer.

Michael Bay is producing, while David Valdes, Chris Bender, J.C. Spink exec produce.

Olyphant is repped by CAA.