"Lost" co-star Cynthia Watros has been tapped to star opposite Tom Cavanagh in CBS' comedy pilot "My Ex-Life."

The project, from 20th Century Fox TV, centers on two best friends (Cavanagh, Watros) who happen to be a divorced couple sharing custody.

Watros replaces Gillian Vigman, who originally was cast in the pilot.

Watros is doing "My Ex-Life" as a guest star because of her commitment to ABC's hit drama "Lost," on which she is a regular.

However, the guest-starring turn in the CBS pilot is sure to raise speculation about the future of Watros' character on "Lost," Libby.

Watros, whose series credits also include Fox's "Titus" and ABC's "The Drew Carey Show," is repped by Innovative Artists and Principal Entertainment.