Actors Thomas Gibson, Matthew Gray Gubler, Kirsten Vangsness, Joe Mantegna, Paget Brewster, Shemar Moore, and A. J. Cook at the 100th Episode Cake Cutting on the set of CRIMINALS MINDS in Los Angeles, CA.Photo: Mark Davis/CBS ©2009 CBS BROADCASTING INC. ALL RIGHTS RESERVED

It sure ticked off Criminal Minds fans when A.J. Cook, who played Agent JJ Jareau on the series, was given the boot.

Rumors suggested all sorts of head-honcho rationale for losing Cook – along with additional threats that co-star Paget Brewster, Agent Emily Prentiss on CM, could get iced from the series as well.

Well, CBS Entertainment President Nina Tassler tells us that the changes in Criminal Minds wasn’t for budgetary reasons, but rather a natural evolution of a successful show…with a major spin-off in the works (Criminal Minds: Suspect Behavior).

Click onto media bar to hear Nina Tassler’s explanation for why Cook is now toast on Criminal Minds and why Paget Brewster will go – if she chooses to do so.