Eric Christian Olsen -- who might have made one too many 'Mama Said Knock You Out' jokes while guesting on the Season 1 of LL Cool J's"NCIS: LA" -- has been promoted to a series regular. His two appearances as LAPD liaison Marty Deeks were enough to convince producers to bring him on full time. "We are thrilled to have Eric join the cast," said Executive Producer Shane Brennan, in a statement released by CBS. "He has already proved himself to be a great asset and invaluable member of the team, and Eric's fans will be delighted to see what we have in store for him."This marks Olsen's first steady gig since the 2007 cancellation of FOX's "The Loop." Since then, he's most notably appeared as Kyle on "Brothers & Sisters" and as the perceptually shirtless Vaughn on "Community." Follow Zap2it and MikeyLikesTV on Twitter and Zap2it on Facebook for the latest TV, movie and celebrity news.