After being seriously injured in an on-set accident in early 2016, 26-year-old actor Dylan O'Brien had to take six months off to recover, putting the third Maze Runner film on hold and delaying his next project, the thriller American Assassin. Now he has completed work on both projects, and it's the second film that hits cinemas first.

Dylan O'Brien in 'American Assassin'Dylan O'Brien in 'American Assassin'

In American Assassin, O'Brien plays black-ops recruit Mitch Rapp, who launches a revenge mission when his fiancee is killed. And he was determined to make the movie. "I didn't want to let it go," he says. "And I also had this really interesting, deeper connection to this character over the course of those six months because of what I was going through. I felt like I could portray that and wanted to be the one to do that justice. It was almost like an honour for me at that point!"

He was drawn to the role from his first reading of the script. "It was just a great role," he says. "I was really taken with the arc of the character. I felt it was realistic as well and operating in a really relevant landscape. I felt like it had strength and it felt really impactful and emotional."

Watch the trailer for 'American Assassin' here:

Of course, training to play a super-fit counterterrorist assassin was rather challenging after his injuries. "I knew it wouldn't be getting back on the horse in a light way," O'Brien laughs. "But I feel a bit embarrassed saying that, because there are guys who do it for real and go through much, much harder times. I just got the actor version! I grew to really enjoy it. I'd never done any martial arts training or tactical gun work. It wound up being a great experience, but it was really hard."

In the end, he found that making the film helped him begin to feel normal again. "I'm really glad that I pushed through and did it," he says, "because it was something that ultimately became really instrumental in that recovery. It was the biggest challenge of my life but it's something that will always be really special to me."

More: Dylan O'Brien is injured on 'The Maze Runner'

And he says he's up for playing Mitch again if fans want a sequel. "They have plenty of source material," O'Brien says. "There are 16 books, so it's a definite possibility and I know that's very much the plan. I'd love to do it again and I'm signed up for more. I think there are plenty of places you could go with this character."