Karen Gillan has teased her Marvel Cinematic Universe character Nebula has a big part to play.

The 30-year-old actress portrays the blue alien assassin in the 'Guardians of the Galaxy' movies and has wrapped up reprising her role in the upcoming 'Avengers: Infinity War' and 'Avengers 4' films, and had no idea Nebula would still be in the MCU.

In an interview with ScreenRant, Gillan said: ''I had no idea that this was where the character was going.

''I genuinely signed on to the role thinking it was eight days of filming and then I was going to die in the first Guardians.

''Three movies later and there's three more to come out it's, like, crazy. It's funny because I read the 'Infinity Gauntlet', which is what the new 'Avengers' films are based on, as research for my character because it's her sort of biggest moment within the Marvel comic book world.

''And then to find out they're making a double-bill feature based on that, I was just so excited actually because Nebula gets some really cool stuff.''

Recently, the star revealed it is a painstakingly long process preparing for the MCU movies as she sits in hair and make-up to get blue skin ''stuck'' to her face for numerous hours each day.

Last year, she said: ''I've been in there [MCU] for a little while now, nearly five years playing this blue bald character.

''It takes four hours in the morning of having a skin stuck on my face.''

'Avengers: Infinity War' will see the hero squad, which includes Iron Man (Robert Downey Jr.), Captain America (Chris Evans), Thor (Chris Hemsworth), The Hulk (Mark Ruffalo), Scarlet Witch (Elizabeth Olsen), Vision (Paul Bettany), Black Widow (Scarlett Johansson) and Hawkeye (Jeremy Renner), join forces with the 'Guardians of the Galaxy' troop to save the Earth.

The two teams will have to work together to fight intergalactic tyrant Thanos, but they will also receive a helping hand from Spider-Man (Tom Holland), Black Panther (Chadwick Boseman), Dr Strange (Benedict Cumberbatch), as well as Captain Marvel (Brie Larson), which will mark the star's debut in a Marvel production.