Sean Gunn has officially "retired" from portraying Rocky Raccoon in the Guardians of the Galaxy franchise.

The 52-year-old actor is best known for playing Kraglin in the movie series but he also provided motion-capture performance for the talking creature - who is voiced by Bradley Cooper - and though no more Guardians of the Galaxy films are currently in the pipeline, Sean admitted MCU bosses will have to find someone else because years of having to crouch have taken a toll on his joints.

Asked if it "hurts after a while" to make himself as small as a raccoon while filming on a green screen, he said on The Brandon Davis Show: "Yes! Everyone thinks it's my knees, but it's really my feet and my ankles.

"I'm in a catcher's crouch, and I'm pivoting a lot on my points of contact with the ground. I'm doing a lot of pivoting in my ankles and feet. And over the years, I think it had a little bit of an effect on my physiology.

"My knees are fine, but since I turned 50 a couple of years ago, I am retired from Rocket. Not that [Marvel has] called, but if they did, I don't think I could do the motion reference for Rocket anymore. I'm too old."

Sean's brother is DC Studios co-CEO James Gunn and the actor has already made the jump from the rival franchise, starring as villain Maxwell Lord in Superman and the season 2 premiere episode of Peacemaker.

And the actor recently insisted Marvel and DC are too different to compare them to one another.

Speaking to The Wrap, he said: "I came into the whole process of working at Marvel once the machine was kind of already up and running smoothly and doing well.

"DC, I've done Suicide Squad, but now they're kind of overhauling it, and it's now ever since my brother took over as head of the studio. It's sort of been a new process for them. So it would be, it's really kind of true, like trying to compare apples and oranges."

Even so, Sean explained that working with both studios felt "similar" to him because he got to collaborate with his brother.

He added: "Underneath it all, working with my brother is more similar than it is different to other things.

"So, the fact that I was working with James in Marvel and James in DC makes it actually … there's a lot more similarities in terms of process."