Tom Hanks helped Karen Gillan through a crisis of confidence.

Karen Gillan

Karen Gillan

The 33-year-old actress admitted she began to flounder in 2017 when her career was taking off around the world but praise from her co-star in sci-fi thriller 'The Circle' helped reassure her about her talents and put her back on the right path.

Karen told You magazine: "Every project I was doing was getting bigger and bigger in scale.

"I had always been totally fearless, and I suddenly found myself dealing with self-doubt."

She told how Tom took her aside on set and said: "You’re really good. Keep going."

She added: "It was the sign I was looking for. To have someone you idolise say, actually, you’re not terrible, was completely trippy. From that point, I worked on my acting and I completely rebuilt."

The Scottish star is best known for her role in the Marvel Cinematic Universe (MCU) as Nebula but she admitted she'd initially only signed on for eight days work on 'Guardians of the Galaxy' but producers liked her so much, they decided against killing of the blue-skinned alien.

She recalled: "I signed up for eight days, and then it just kept getting extended. So I was meant to die, and then just got brought back to life.

"I was still living in Inverness when I auditioned for that role, which made the whole experience less intimidating.

"I was able to go from my childhood home to the studio in London, and when I came home, my parents would be like, 'Great, well done, now bring your laundry down.' "

And Karen admitted she's still adjusting to being a part of the vast superhero world and finds it "crazy" that she socialises with co-stars including Chris Evans, Robert Downey Jr. and Scarlett Johansson.

She laughed: "I would be thinking, 'This is absolutely crazy'. But also… 'This is going to make a great story to tell the grandkids.' "