Although there was never really any doubt, Marvel made it official that Vin Diesel will voice the tree-like Groot in director James Gunn’s “Guardians of the Galaxy.” The announcement came just hours after the star of the “Fast and the Furious” franchise posted on his Facebook page the above photo of himself posing with a detailed bust of the character. Diesel had been hinting of his involvement in the Marvel film — or at least a Marvel film — since late June, with it becoming clear by mid-August that he was up for the role of Groot.

While the Marvel Studios press release states only that Diesel will “lend his booming voice to the role,” the actor released a video in October that showed him practising walking on stilts, indicating he’ll also do motion-capture work . In the video, he revealed he has just one line of dialogue in the film– presumably, “I am Groot!”Opening Aug. 1, 2014, “Guardians of the Galaxy,” also stars Chris Pratt as Peter Quill, aka Star-Lord, Zoe Saldana as Gamora, Dave Bautista as Drax the Destroyer, Lee Pace as Ronan the Accuser, Michael Rooker as Yondu, Bradley Cooper as Rocket Raccoon, Karen Gillan as Nebula, Djimon Hounsou as Korath, Benicio del Toro as The Collector, John C. Reilly as Rhomann Dey, and Glenn Close as Nova Prime. (Melrose, 2013)