Execs on the Fox lot were scratching their heads Monday, wondering when and how Chase Carey may be returning to the News Corp. fold — and what it means for them.

Given Carey’s lengthy experience at News Corp., his name had always been discussed as the exec most likely to fill the void left by Peter Chernin’s departure from the conglom. But Carey’s contract as prexy-CEO of DirecTV Group extends through 2010, so such a move was seen as unlikely — until word spread Sunday that Rupert Murdoch was in advanced talks with Carey.

Another reason execs didn’t see Carey coming back into the picture was a very strict nonpoaching clause included in the 2008 agreement between News Corp. and Liberty Media that saw News Corp. swap its stake in DirecTV in exchange for Liberty’s preferred shares in News Corp..

Nonetheless, most execs inside News Corp. believed Monday it was a question of when — not if — Carey would return to News Corp., where he’s expected to be named vice chairman.

Given the obstacles the hire still faces, an announcement doesn’t appear to be imminent. But insiders note that News Corp. topper Murdoch is tenacious when it comes to going after things he wants — witness the time and energy put into acquiring DirecTV in the first place or, more recently, Dow Jones. Now, Murdoch is said to be keen on the idea of bringing in Carey to serve as his chief strategist and help him manage the conglom’s assets after Chernin exits his post as Murdoch’s No. 2 later this month.

Meanwhile, others point out that Liberty chief John Malone knows how to exact a pound of flesh when he has something someone else wants — and that he’ll likely be willing to let Carey go, but at a steep price to News Corp.

What Malone may demand from News Corp. is anyone’s guess at the moment. But Malone is said to be looking at shopping Liberty’s stake in DirecTV. The company has announced plans to combine DirecTV with Liberty’s entertainment assets, creating a new company that would be run by Carey.

As for Carey, it’s believed he began entertaining the idea of returning to News Corp. in part because the future of DirecTV as a standalone company has become unclear. He’s also believed to be interested in having a New York base. (DirecTV is headquartered in El Segundo, Calif.)

Complicating matters: Although Murdoch first sold Carey on the job as chief strategist, Carey is said to be interested in returning only if he also has some direct reports.

That means that, at least on paper, Fox Filmed Entertainment toppers Tom Rothman and Jim Gianopulos, who now oversee the film and TV studio operations, and Fox Networks Group chief Tony Vinciquerra would report to Carey.

So far, only Murdoch knows exactly how he plans to incorporate Carey into the conglom’s structure — and he’s not sharing that information just yet.

Murdoch first put Carey in charge of DirecTV in 2003, after News Corp. acquired the controlling interest in the satcaster from Hughes. He stayed on even after News Corp. cut its asset swap deal with Liberty.

Before that, Carey had been in the News Corp.-Fox fold since 1988, when he rose through a series of exec posts at Fox Television and Fox Entertainment Group. He served as co-chief operating officer of News Corp. alongside Chernin from 1996-2002.

A News Corp. spokeswoman declined comment, while a DirecTV spokesman said the company wouldn’t comment on “rumors and speculation.”