Los Angeles: `Castle` star Nathan Fillion will be a part of James Gunn`s `Guardians of the Galaxy`.
Gunn had initially denied the rumours that Fillion, 43, would star in the film, but later confirmed the news, saying he has a cameo in the film, suggest reports.
"@nathanfillion has a very small fun cameo he did as a favour to me," Gunn tweeted.
Fillion, in April, had hinted at his possible appearance in `Guardians of the Galaxy`.
Asked if he wanted a part in the Marvel superhero movie, he had replied, "Wanting to get a part....Or maybe did."
"Maybe you`ll be surprised. Maybe. Check the credits," he had said.
Gunn has directed the action film with a script which he co-wrote with Chris McCoy. The movie is slated to release in US theatres on August 1.