Did CBS derail Cuoco's 'Grey's' gig?

It appears the case of Kaley Cuoco's disappearing Grey's Anatomy guest stint has been cracked!

Although the actress' rep says an unforeseen "publicity commitment" forced the Big Bang Theory star to back out of a top-secret appearance on Grey's Anatomy's May 14 season finale, multiple sources now tell me that it was her current employer, CBS, that put the kibosh on the deal. An Eye spokesperson couldn't be reached for comment, but as one insider explains, "They didn't want one of their biggest stars appearing on one of ABC's biggest shows."

As a result, Grey's has tapped former O.C. starlet Shannon Lucio (she played Caleb's illegitimate daughter, Lindsay) to fill Cuoco's shoes.

Still unknown: Who the heck is she playing? Some of you initially (and understandably) speculated that, based on Cuoco's resemblance to Katherine Heigl, perhaps the character is a relative of Izzie's. That possibility seems less likely with the casting of Lucio... or does it? ABC isn't spilling, so I once again open the floor to you guys: Do you still think there's an Izzie connection to this character? And getting back to Cuoco, can you understand why CBS might not be keen on loaning her out to the competition? Sound off below! (source)