The series, which had a recent 28 percent ratings gain, features Hilty as Liz, Sean’s long-time friend and co-worker who is a former therapist. She replaced Lindsay Sloane, who played the role in the pilot.

Hilty most recently played aspiring Broadway star Ivy Lynn on "Smash." Her stage credits include 9 to 5, Gentlemen Prefer Blondes and Wicked.

In addition to Hayes and Hilty, the cast of "Sean Saves The World" includes Linda Lavin (The Lyons, Collected Stories), Thomas Lennon (“Reno 911") and Echo Kellum (“Ben and Kate").

"Sean (Sean Hayes, 'Will & Grace') is a divorced gay dad who juggles a lot — his successful but demanding career, offbeat employees, pushy mom Lorna (Linda Lavin, 'Alice'), and weekends with his teenage daughter, Ellie (Sami Isler)," press notes state. "So when his 14-year-old bundle of joy moves in full-time, it's a whole new world. From keeping his boss happy, his employees motivated and enduring his mother's tactless 'advice' to raising a smart, grounded and healthy kid, it's going to be a growing experience, to say the least."

Hayes received a Tony Award nomination for his performance in the 2010 revival of Promises, Promises and hosted the 2010 Tony Awards. Hilty and Hayes previously worked together on "Smash," where Hayes guest-starred as a Hollywood actor making his Broadway debut.

Visit NBC.com/Sean-Saves-The-World.