Guardians of the Galaxy Vol. 2 star Vin Diesel says Baby Groot was 'so fun to play'

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In Guardians of the Galaxy Vol. 2 (out May 5), walking plant Groot is not only reduced in size but also has a much higher, child-like speaking register. So how much audio processing was involved to make Vin Diesel, who voices the character, sound suitably pipsqueak-ish. The answer is not much at all, according to the film’s writer-director James Gunn.

“Very little, very little,” says Gunn. “I mean, there’s a tiny amount of processing that we do on a few of our characters, but it’s very little. It’s mostly just Vin’s voice. He’s able to, you know, speak in a much higher register than he normally does.”

To be honest, we did not know that.

“Listen, yeah, Vin’s an actor!” continues the director. “One of the reasons I was interested in working with Vin is I like Vin’s early [work], when I first saw Vin come around in movies like Boiler Room. He’s a real actor! He’s become this sort of larger-than-life action figure. But he’s actually are a real actor who can do a lot of different things. I’d love to see him take on some more difficult roles in his career, because I think he’s more than capable of doing that.”

Diesel himself certainly sounds more than happy to be playing a different, ahem, branch of the Groot persona.

“He has always had an innocence,” says the Fast and Furious franchise star. “But this time he has a fun a certain naive aspect because he really is just a baby. That was so fun to play. Groot is such a fascinating character on so many levels. For this installment I needed to not only pitch up the performance, I needed to embed even more wonder than he usually possesses… and he always has a wonder about him already. So proud of the character and what James Gunn has done with him.”