Even though Vin Diesel is on the set of Fast and the Furious 7, he is making time to practice for his role in Guardians of the Galaxy. He will be Groot, the 7 and a half foot tree. The video which was posted on his Facebook page shows Vin Diesel Practicing for his role as Groot while interacting with some of the Fast 7 cast members.
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After the defeat of the Phalanx, Groot joined the Guardians of the Galaxy a proactive peacekeeping team assembled by Star-Lord. Vin Diesel is in talks to portray the character
Apparently he will only have one line in the movie? Here’s the video:
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[Source]
The only line Vin has: I AM GROOT. He’ll just have to come up with 20 or so different ways to say it.