This is rarely promising news for a show:

Sons of Tucson is recasting a pair of key roles.

The sitcom, which stars Tyler Labine (pictured) as a slacker enlisted by a trio brothers to pose as their father while their real dad serves time for a white-collar crime, is seeking two new actors.

A pair of sons - Robby, 8, and Brandon, 15 - will be replaced.

They were originally played by Troy Gentile and Davis Cleveland. No word yet on why the show is seeking their replacements.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.