Charlie's estranged wife Denise Richards and their baby daughter SAM have already appeared on the show, and now the actor reveals that his dad has signed up for a guest spot.
He says, "He's gonna do our show, not playing my father, which is funny in itself. He's gonna be somebody's father on the show, one of the co-stars. I don't want to give too much away."
Martin and Charlie Sheen have acted together a handful of times before, including in the 1987 movie Wall Street and the 1990 military drama CADENCE. Martin also made a guest appearance on Spin City during Charlie's tenure on the show.