Which Meddling 'Grey's Anatomy' Doc Have Producers Marked D.N.R.?

Though Grey's Anatomy has shown an interesting set of priorities this season (less lesbians, more ghost fucking), part of its topsy-turvy plotting may have to do with a star that producers are punishing with reduced screen time. E!'s Kristin Dos Campos has the blind item:

A source close to the show tells me, "The reason [the actor] has not been on is because [he or she] has been a pain in the ass lately, trying to change scenes and dialogue, being hard to work with and putting up an attitude. The higher-ups were getting tired of it, so they tweaked [him or her] out of some episodes. That's why you haven't really seen [him or her] lately."

A second source seconds that emotion: "[He or she] is not really getting along too well with producers right now."

So who are the likely culprits? Patrick Dempsey has publicly implied his disapproval with story decisions this year, but hasn't suffered a notable scaling-back on-screen. Meanwhile, go-to Grey's problem girl Katherine Heigl is currently enmeshed in the most ridiculous, high-profile storyline the show has right now: boffing the equivalent of her imaginary friend.

Thus, we're left to conclude it's T.R. Knight who attempting to salvage his scenes and getting them cut in the process, especially since Knight's George has barely registered this season. EW's Michael Ausiello has posted a similar blind item that implies an original cast member of a hit show may be permanently excised — will Knight be the next to fall under the Grey's casting scalpel?