Murphy and Zayas join a cast that features Stallone, Jason Statham, Mickey Rourke, Jet Li, Dolph Lundgren and Randy Couture.
The movie follows a team of mercenaries on a mission to overthrow a South American dictator.
Murphy will play Rourke's singer girlfriend. She will perform a song in the film. Zayas will play the dictator in question.
The Expendables started shooting this week in Brazil.
The Expendables was released August 13th, 2010 and stars Sylvester Stallone, Jason Statham, Jet Li, Dolph Lundgren, Eric Roberts, Randy Couture, Steve Austin, David Zayas. The film is directed by Sylvester Stallone.