'Lightyear': Here's why Chris Evans replaced Tim Allen in the 'Toy Story' spin-off

Watch: Lightyear trailer

Buzz Lightyear is back. Three years after the release of Toy Story 4, one of Pixar's most iconic characters is returning to the big screen with his own spin-off film.

Lightyear, which flies into cinemas today, tells the origin story of the action figure and his adventures to infinity and beyond.

But the character sounds a little different to the Space Ranger who appeared in all four Toy Story movies.

That's because Tim Allen, who voiced Buzz Lightyear in the beloved franchise, has been replaced by Marvel star Chris Evans.

The move to recast Allen has prompted confusion from fans, but there is a simple reason why Evans was picked to be the new voice of Buzz.

Why isn't Tim Allen voicing Buzz in Lightyear?

Lightyear isn't about the Buzz Lightyear toy featured in the Toy Story films. Instead, it focuses on the hero who inspired the toy.

"I've always wondered what movie was Buzz from," director-screenwriter Angus MacLane told Yahoo earlier this year.

"Why couldn't we just make that movie? So that's what we did.... [Lightyear is] the movie that Andy saw that changed his life… Andy's Star Wars."

Pixar took the decision to replace Tim Allen with Chris Evans in the spin-off because they wanted to differentiate between the two characters.

MacLane told Vanity Fair last week: "Tim's version of Buzz is a little goofier and is a little dumber, and so he is the comic relief.

"In this film, Buzz is the action hero. He's serious and ambitious and funny, but not in a goofy way that would undercut the drama.

"Chris Evans has the gravitas and that movie-star quality that our character needed to separate him and the movie from Tim's version of the toy in Toy Story."

What has Chris Evans said about the role?

Evans has admitted that taking on the role of Buzz Lightyear was "intimidating".

The actor, best known for his role as Captain America in the Marvel Cinematic Universe, said: "I used Tim Allen as a guideline.

"He did such a good job, and I'd be a fool not to acknowledge the work he did. But I couldn't just do a shameless impression.

Read more: 22 Disney and Pixar in-jokes that will blow your mind

"I had to somehow create my own understanding of the character, and try to make some fresh tracks in the snow while paying homage to the great work that he did.

"Eventually I felt comfortable enough to make my own interpretation, and part of that was lowering the tone of my voice. I basically have to lower the register of my voice in everything that I do."

Who else is in the Lightyear cast?

Lightyear follows Buzz after he is marooned on a hostile planet 4.2 million light-years from Earth.

He must work with a group of new recruits, including Mo Morrison (Taika Waititi) and Darby Steel (Dale Soules), to find a way back home.

The mission is commanded by Alisha Hawthorne, voiced by Orange is the New Black star Uzo Abuda.

James Brolin plays Buzz's arch-nemesis Emperor Zurg, while Keke Palmer voices Alisha's granddaughter Izzy Hawthorne.

Peter Sohn, who directed Pixar's 2015 film The Good Dinosaur, lends his voice to Buzz's robot cat companion Sox.

Lightyear is out in cinemas now