Long before he lorded over the Shameless Gallagher clan, William H. Macy was eyed to play the Griffins’ family pet — but "Family Guy" creator Seth MacFarlane opted to lend his own voice to the pooch instead.

“I look back and I’m like, ‘How cocky and arrogant must I have been at 24 to have Bill Macy audition for Brian and go, ‘You know what? I don’t think it’s working and I’m going to do it myself’?” recalled MacFarlane. “The hubris is not to be believed!”

https://tvline.com/lists/tv-actors-almost-played-different-roles/william-h-macy-family-guy/