Gibson was let go from the film after reports that several cast members complained about his inclusion, prompting director Todd Phillips to claim that the actor's presence would disturb the "family environment" of the movie.
However, during an appearance on NBC's Today Show on Monday morning, Galifianakis said that he did not complain about a possible Gibson appearance.
"I do not consult on the movies that I'm in. I just show up and I say my lines, usually terribly, and I do consult on dialogue," he explained.
"But as far as hiring and firing of actors, I have no insight into that world whatsoever."
He went on to joke that while he would not reveal his personal opinions on Gibson, he would be happy to discuss the singer of the same last name.
"If you have any questions about Debbie Gibson, I can answer that. Debbie Gibson, if I remember correctly, lives in this neighbourhood and has a very nice toilet."
Galifianakis previously admitted to being "frustrated" with The Hangover 2.