Guardians of the Galaxy Groot: Vin Diesel Teases 'Guardians of the Galaxy' Role, Voicing Groot in Marvel Superhero Film?

Vin Diesel is at it again with more cryptic photo messages on his Facebook page.

The actor posted the following photo of the Marvel character Groot to his Facebook page on Sunday with no accompanying explanation:

For those unfamiliar with the character, Groot is a plant monster from Planet X who originally came to Earth to capture and study humans. He eventually teams with the Guardians of the Galaxy and helped the superhero team combat multiple threats.

As MStars previously reported, Diesel posted on his page back in June that he had a meeting with Marvel but did not know why the company wanted to see him. He then posted in July that he had that meeting but did not say what the two sides discussed.

IGN reports that Diesel said at San Diego Comic-Con 2013 in July that news would come out by the end of the month about his Marvel role. Halfway through August, no official news or announcement has come from Diesel or from Marvel Studios.

The film is set for release on Aug. 1, 2014 and will star Chris Pratt, Zoe Saldana, Dave Bautista, Michael Rooker, Ophelia Lovibond, John C. Reilly, Enzo Cilenti, Lee Pace, Karen Gillan, Glenn Close and Benicio Del Toro. James Gunn wrote the superhero film and will also direct it.