After being cast -- and then replaced by Liam Neeson -- for a comedic cameo in the sequel to the hit 'The Hangover,' Mel Gibson is downright "furious" with producers of the film, according to Page Six.

An insider says, "He doesn't understand why Mike Tyson, a drug user [and convicted rapist, as points out] who turned his life around, was given a chance while Mel was kicked to the curb. Everybody deserves a second chance."

Gibson seemed to be making inroads on his career comeback -- after his public image was disastrously damaged over the summer by recordings of his angry rants to his ex-girlfriend, Oksana Grigorieva -- however, the news of his casting in the 'Hangover' sequel was immediately followed by rumors of dissent among the cast. Gibson was swiftly dismissed, and the role of the tattoo artist went to Neeson.