Guardians Of The Galaxy Vol 2: 20 New Details Just Revealed

As already revealed, it's Rocket who is the key to the Sovereign getting pissed at the Guardians, and it seems to be that he's still not entirely used to his new place in the group. Sure, he's Groot's protector (in a reversal of their roles in the first movie), but the idea of family doesn't sit naturally with him.

Perhaps it's because of his past - which Gunn says "affects his relationship with the other Guardians" - that he isn't quite able to accept his part in the team?

"...It’s about Rocket really trying to- As I’ve said before, I relate to Rocket more than any of the other characters, and this is really about Rocket coming to terms with accepting his place within a group of people, which probably seemed like a good idea for two seconds when they were getting along and saving a planet. And now he’s just not very comfortable with the idea of being a part of this group, which come to think of it, is probably what I’m like with everything in making this movie."

Presumably, that's going to be the tale of his arc, and hopefully he doesn't learn how to belong just before he's killed off...

Gunn meanwhile says that Groot will be a far more rounded character than he was first time out, thanks to a change in the way he was present in scenes:

"The guy playing Groot was a stand-in on the last movie and so he was there we just kind of always forgot he was there. He doesn’t talk very much, so you’re doing all these scenes and when we have the scenes in the movie where they turn to Groot and Groot’s like “why are you forgetting me?” That’s really what we felt like while we were shooting the first film."

And if you're wondering why he's wearing a costume (it's a Ravager costume, not a Star-Lord jacket) there's an answer for that too, as Kevin Feige confirmed...

"He only has it very briefly and that is a Ravager costume. The very mean Ravagers sort of quickly sew and put him in, because they think it’s funny. Groot does not think it’s funny."