Teaser: The Office new boss to be a new cast member?

Surely, after all this stringing out of the new Office boss talk (which realistically began soon after Steve Carrell's departure was announced), they wouldn't introduce another outsider into the mix?

Well that seems to be the case, as, in addition to James Spader, there will be another addition to the cast, who may step into the boss' chair. 

Here's the quote from NBC Chicago:

"...they've kept a lid on the revelation of a SECOND major cast add, a mysterious someone who'll step into the Scranton managerial seat vacated by Carell"

With all the Kutcher-Two and a Half Men talk, it seems to have overshadowed this big reveal. 

But you'll still have to wait until Thursday night (Friday, AU time) to find out the real answer- will someone really overtake Daryl, Andy or Dwight?