The part won't be too big of a stretch for Armstrong: He will play himself and will befriend Adam (Oliver Hudson). An airdate for his episode has not yet been determined.
Best known as Booger in Nerds, Armstrong has also co-starred in Risky Business and Ray. On the small screen, he recurred on Moonlighting as Herbert Viola and has guest-starred onGrey's Anatomy and House. Earlier this summer, he started a multi-episode arc on The Closer.
Rules of Engagement premieres Saturday, Oct. 8 at 8/7c on CBS.