Nathan Fillion fans rejoice! The Firefly and Castle star’s “very fun cameo” in Marvel’s Guardians of the Galaxy has been confirmed by director James Gunn.

Start trying to figure out Fillion’s cameo, as it’s now been confirmed the Firefly actor will be joining the incredible cast that will make up Marvel’s upcoming film Guardians of the Galaxy.

While he won’t be playing a major character, director James Gunn has confirmed that Fillion will have a cameo in the highly anticipated film including actors Chris Pratt, Zoe Saldana, Bradley Cooper and Karen Gillan.

Early rumors suggested that Fillion would be playing a larger role in Guardians of the Galaxy, but his friend and director James Gunn has now revealed via Twitter that it will simply be a cameo.

Fans were already incredibly excited about Guardians, but this takes the film’s geek-factor to the next level. When asked about Fillion playing ‘Nova,’ as rumored, Gunn Tweeted:

After some begging from Fillion fans, Gunn revealed for the first time that his friend would in fact have a very fun cameo:

As fans continued their attempts to get more info about Fillion’s role from Gunn, he offered some reassurance that he would “never lie to fans”:

Despite Nathan Fillion’s role being small, as fans we’re incredibly excited to find out for certain that he will have a cameo in Guardians of the Galaxy.

The actor has a massive following due to his many interesting sci-fi roles and Guardians looked like it would have been the perfect film to give the actor a beefy, comedic role. But, we’ll take a cameo in Marvel’s highly anticipated film featuring a remarkable cast.

James Gunn also revealed that Fillion did the cameo “as a favor,” which is interesting to hear. We can’t wait to find out what character he’ll be playing and we imagine Gunn has done something extremely exciting and quirky with the popular actor.

Guardians of the Galaxy’s recent trailer gave us some great looks at Chris Pratt and Zoe Saldana, and more importantly, showed us quite a bit more of Bradley Cooper voicing Rocket Raccoon. It looks as though he’ll be quite talkative in the film.

Guardians of the Galaxy’s release date is set for August 1, 2014. Featuring an intergalactic group of Guardians, led by Star-Lord, they make a desperate stand to save the galaxy.

Two-time Academy Award nominee Bradley Cooper voices the machine-gun-wielding Rocket Raccoon and is joined by Vin Diesel as the tree-like Groot, with Zoe Saldana, Chris Pratt, Karen Gillan and Dave Bautista filling out the leading roles.

What role/cameo would you want to see Nathan Fillion playing in Guardians of the Galaxy?