There are certain actors that you just wish would break away from the steady stream of supporting roles they're getting and become the star of the show. For years, the person most cited in that category was Paula Marshall, who left a trail of memorable supporting roles and failed series in her wake before landing on 'Gary Unmarried.'

Now, I'm afraid that one of my favorite current actresses, Judy Greer, is falling into that category. Since her one and only starring series project, 'Miss Guided,' failed two years ago, we've seen her in a series of supporting roles, in all of which she's been excellent.

Just over the last couple of months, she's played Phil Dunphy's amorous ex-flame on 'Modern Family,' and last night she played Sheldon's super-amorous astrophysicist friend on 'The Big Bang Theory.' And next week, she'll play a (probably) amorous date for the perpetually single Ted on 'How I Met Your Mother.'

Sensing a pattern here, folks?

Take a look at Greer's IMDb profile, and most of the roles she plays, whether on TV or in the movies, fall into one of two categories: 1) the nerdy but cute best friend, or 2) the nerdy but cute sex kitten. And, don't get me wrong, she does a great job in either role. But at this point, those two roles are ones she can do in her sleep.

'Miss Guided,' as mediocre as it tended to be, showed what Greer can do when given a starring role. As insecure guidance counselor Becky Freely, we saw Greer play confident and vulnerable, and we saw her when her character felt sexy as well as ugly. The conceit of the series, that Becky's back in her old high school, and the same high school feelings and cliques occur even amongst the faculty, was reflected well in her performance. And it goes without saying that she displayed the same knack for physical humor that's been a hallmark of all her roles.

When the show premiered, NYMag.com's Vulture blog put Greer in a category of tough-to-cast comic actresses that included Joan Cusack, Tea Leoni and Bonnie Hunt. But, at the very least Cusack has gotten two Oscar nominations, Leoni had a period where she was a bankable movie lead, and Hunt has had more than one chance to make a TV splash. Greer has gotten that one and only chance to prove she could carry a show.

I'm wondering if producers have just decided that Greer is better as a supporting character, like she is in 'Archer,' or as a superstar guest actor. That would be too bad, because she deserves another chance. And, besides, how many times can we see Greer play the best friend / sex kitten without getting tired of it?

[Follow @joelkeller on Twitter.]