James Gunn, director of Marvel's 'Guardians of the Galaxy' film, has just confirmed that one of his old friends will be appearing in the movie as a cameo.

The director responded to a question on Twitter from @STARS_TyranT about rumors circulating that actor Nathan Fillion, famed for his role as Captain Malcolm Reynolds on the short-lived sci-fi television series 'Firefly,' would have a role in 'Guardians of the Galaxy.' Given that Fillion has appeared in films of Gunn's like 'Slither' and 'Super,' it wouldn't be too far of a stretch to believe he might appear in 'Guardians.'

Gunn responded with the following:

Many fans who saw that tweet immediately started guessing what role Fillion would have, positing that he'd play Nova, otherwise known as Richard Ryder, or maybe even a S.H.I.E.L.D. agent. Gunn was quick to squash the rumor that he'd play the former.

Whatever role Fillion will play, we'll have to wait until 'Guardians of the Galaxy' is released in theaters on Aug. 1.