Vin Diesel recently posted the picture above on his Facebook page with the following caption:
Some of you may remember the character I voiced back in 1998… Last month I had the opportunity to voice a new character, on the Disney lot… and I was shocked to see the same sound engineer, Doc, who was there when Brad Bird was directing me 15 years earlier, as the Iron Giant. As artists we are susceptible to clocking omens… and this was a great sign. As I worked, with James Gunn, breathing life into GROOT… I saw more and more of the film… wow. /smile
P.s. This summer's Guardians of the Galaxy, is going to blow you away… Grateful for the opportunity to make magic...
Sounds like Vin is already finished recording his part as Groot and is very excited about it. Personally, I think he's going to do an excellent job.