Though we've yet to hear an official, Marvel-stamped confirmation of Vin Diesel (The Fast and the Furious) voicing the tree-like Groot in Guardians of the Galaxy, the actor himself all but verified it during a recent press event.  Just a couple of days ago, Diesel put up a not-so-cryptic image of Groot on his Facebook page, which made some sense considering he had mentioned ties to an upcoming Marvel picture during Comic-Con.  The secretive studio may have their hands full with Diesel, who likes to be an open book with his legions of fans, but a little speculation can go a long way towards generating interest for Guardians, which will be Marvel's toughest sell to date, despite its fantastic cast.

Starring Chris Pratt, Zoe Saldana, Dave Bautista, Lee Pace, Benicio Del Toro, Karen Gillan, John C. Reilly, Glenn Close, Michael Rooker, Djimon Hounsou, and Peter Serafinowicz, James Gunn's Guardians of the Galaxy opens August 1, 2014.  Hit the jump to see what Diesel has to say about his upcoming voice role.

As Hero Complex reports, Diesel wasn't exactly cagey when it came to talking about his role voicing Groot:

Hero Complex: OK, so why Groot?

Vin Diesel: I’m an actor. I can do whatever the … I want. As an actor, not everything has to be the most obvious choice. And sometimes, the best thing you can do — as far as Steven Spielberg and his advice — is to defy expectations. So if everybody thinks you’re going to go for this one thing and you flip it entirely and go for the strangest Marvel character, it’s interesting. And when something is interesting, it’s inspiring.

Why did you post a picture of the character on Facebook this weekend?

Diesel: I get inspired by things. So if somebody sends me a book of conceptual art that’s the best character design work I’ve ever seen — I’m not kidding, I see that and I want to be a little cryptic and I want to say something positive. Even if it’s as cryptic as an old, dated image of a character.

Marvel is notoriously secretive about its movies, and you’re very open. Isn’t it mad you’ve been dropping hints about “Guardians”?

Diesel: The last thing they are is mad. I’m pretty open, but I have been secretive about this. I went to Comic-Con and I got blasted while I was on the Hall H panel for “Riddick.” Someone asked a Marvel question. I couldn’t say anything because of that secrecy.

Be sure to head over to Hero Complex for the rest of the article.  And for those of you who weren't aware, this wouldn't be Diesel's first time voicing an animated character.  Check out this throwback featurette from Brad Bird's The Iron Giant below: