It's Official: Bradley Cooper to voice Rocket Raccoon

This was rumored earlier in the week, but it's been made official that Bradley Cooper (Silver Linings Playbook) will voice Rocket Raccoon in Guardians of the Galaxy. Marvel made the announcement today. Now to wait and see if Vin Diesel is actually voicing Groot and we'll be all set.

"Rocket Raccoon has finally found his voice!
Academy Award-nominated actor Bradley Cooper has officially joined the cast of Marvel’s “Guardians of the Galaxy,” lending his voice to the fan-favorite raccoon that will join Peter Quill (Chris Pratt), Gamora (Zoe Saldana) and Drax (Dave Bautista) on their epic adventure.
Cooper has previously starred in “Silver Linings Playbook,” for which he was nominated for an Oscar®, “Limitless,” “Place Beyond the Pines” and the “Hangover” trilogy, the latter of which has grossed $1.4 billion globally. He will next be seen in “American Hustle” which will reunite him with “Silver Linings Playbook” director David O. Russell. “Guardians of the Galaxy” will mark Cooper’s first voiceover work.
In the far reaches of the Marvel Cinematic Universe, an unlikely cast of characters including Peter Quill, Gamora, Drax, Groot and Rocket Raccoon must join forces to defeat a cosmic force of epic proportions. Directed by James Gunn, the live-action “Guardians of the Galaxy” will take fans to new corners of the Marvel Universe when it hits theaters August 1, 2014, but in the meantime stay tuned to Marvel.com for the latest news as it breaks, including official casting, first looks and more!
In addition to “Guardians of the Galaxy,” Marvel Studios will release a slate of films based on the Marvel characters including “Thor: The Dark World” on November 8; “Captain America: The Winter Soldier” on April 4, 2014; “Avengers: Age of Ultron” on May 1, 2015; and “Ant-Man” on November 6, 2015."

Bradley Cooper offered Guardians of the Galaxy voice role

Filming for Guardians of the Galaxy is currently underway, but there are still some characters that have not been cast. Those would be Groot and Rocket Raccoon. Vin Diesel is apparently on board to voice Groot but it hasn't been officially put through yet, but the rumor now is that Bradley Cooper (Silver Linings Playbook) has had the offer to voice Rocket Raccoon extended to him.

James Gunn has expressed his love for Rocket Raccoon and has stated a big factor in him even directing Guardians of the Galaxy was because of that character. However, this is a rumor about an offer so if it's true at all it is possible that Bradley Cooper might not accept the role. There is some possibility as Cooper does have some down time as the filming for American Sniper has been delayed after Steven Spielberg dropped out, but there is no guarantee. We will just have to wait for an official press release on this one. Marvel is pretty secretive about their casting news until they want people to know.