While we all known Bradley Cooper ended up getting the part, Gunn let it be known they actually considered using Danny DeVito, but decided against it because of DeVito’s age.
“In all honesty, Danny DeVito is one of the voices we tried out, but Danny DeVito is an older man now and Rocket is not an older man, he’s a younger man,” Gunn explained. “Danny DeVito’s voice just wouldn’t work.”
Gunn also let it be known that Thanos was the villain in the original Guardians of the Galaxy script, and also that he isn’t a big fan of the Guardians of the Galaxy animated sound track.