Nathan Fillion will always accept James Gunn roles

Nathan Fillion will always say yes to James Gunn.

The 48-year-old actor didn't hesitate when he was offered a role in 'The Suicide Squad', and he heaped praise on the filmmaker's skills as "an amazing storyteller" while admitting there was no chance of him turning down the part.

He told 'ET Canada': "James Gunn, one of the people in my life that when he calls I just say 'Yes to whatever you're about to say. It's yes, the answer's yes.'

"James Gunn is an amazing storyteller. That guy understands story, and he loves to tell story.

"So when he wants to do something you know it's gonna be fun, you know it's gonna be satisfying."

The former 'Firefly' star - who will join the likes of Margot Robbie, Viola Davis and Jai Courtney in Gunn's sequel to the 2016 comic book blockbuster - recently admitted he's getting nervous because he's so desperate to avoid revealing any script secrets to fans.

He jokingly explained: "I start to sweat a little bit when people start getting close to what I would consider something that's actually accurate. I'm the worst liar."

The first 'Suicide Squad' movie was widely slammed by fans and critics, and director David Ayer previously revealed he is tired of being slated for something that didn't match his "original vision".

The filmmaker responded on Twitter after a reporter described the film as "some dumb piece of s**t" while slating Warner Bros.' decision to make a sequel.

He wrote: "That's really mean spirited. I understand the nature of your job and the necessity to grab eyes.

"But a lot of people dedicated their blood sweat and tears and came together to make the original. It's incredibly painful to have two years of my love attacked in such a way. (sic)"