Director Terry Gilliam lined up Depp in 2000 to star as advertising executive Tony Grisoni in the movie, originally entitled The Man Who Killed Don Quixote.
A series of disasters delayed production of the oddball epic, prompting the Pirates of the Caribbean actor to bow out.
Now the 68-year-old film-maker is said to be eyeing Irish actor Farrell as a possible replacement as he finally gears up to begin filming next year (10).
A source tells Britain’s Daily Express, “Terry is a fan of Colin and it’s felt he’s one of the few people capable of filling Johnny’s shoes.
Both Depp and Farrell were among the stars who stepped in to help Gilliam complete his 2009 adventure The Imaginarium of Doctor Parnassus after its star Heath Ledger passed away last year (08).