The actress was a big signing for bosses ahead of the premiere of the relaunched series, but has failed to impress viewers.
Production sources told TMZ.com that she's the only member of the cast of the first series of the reboot not to be invited back for the second, with an insider adding, "Producers found Mischa's storyline a bit bland, and her personality a little boring. Bottom line, she wasn't bringing much drama to the show."
Now execs are said to be considering a replacement for the former star of "The O.C.", with potential candidates allegedly including socialite Caroline D'Amore.
Brody Jenner is among the original cast members set to return for the second series, with TMZ reporting he negotiated a new deal with bosses which will see him bring in around $50,000 an episode.