07/12/2013 09:35 am ET Updated Sep 27, 2013

Sonya Walger On 'Parenthood': 'Lost' Actress Joins Season 5 Of NBC Series


It looks like Julia (Erika Chirstensen) has some competition: "Lost" alum Sonya Walger is headed to "Parenthood," and she has her eye on Joel (Sam Jaeger).

Walger has joined the NBC series as "Pete" (formerly known as Meredith), a "sexy, confident fireball of an architect" working with Joel, according to TVLine.

In the season premiere, Joel reportedly invites Meredith over for dinner, where she makes Julia -- who recently quit her job as a lawyer to be a stay-at-home-mom -- feel inferior and a little threatened.

In addition to the news of Walger's casting, Matt Lauria has officially signed on to continue his role as Amber's (Mae Whitman) love interest Ryan York and is rumored to appear in about half the episodes of the new season.

"Parenthood" returns for Season 5 on Thursday, September 26 at 10 p.m. ET.