'Criminal Minds' has had more than its fair share of drama off-screen in the last year or so. Cast members have been demoted, or promoted then axed, or fired and then rehired. Now comes news that star Thomas Gibson is still between contracts.

According to Deadline.com negotiations have stalled between Gibson and CBS with only one month to go before production gets underway on the upcoming Season 7. While he is expected to sign a new deal to stay with the show the uncertainty is making life hard for the writers.

They have already started to map out next season and write scripts. Gibson's character, Supervisory Special Agent Aaron Hotchner, has been key to the show's storylines, so it would be hard to plot the season without knowing if he will be back.

Back in June we told you how, despite axing AJ Cook and reducing the number of episodes Paget Brewster appears in, 'Criminal Minds' producers said they were looking to hire a new female series regular.

Now we hear that they've kept their word. According to deadline.com Rachel Nichols ('Alias,' 'Star Trek') is in talks to join the drama as a series regular. If she signs, it will make her the first new regular addition since Joe Mantegna in 2007.

Meanwhile, producers are also said to have approached Paget Brewster -- who is almost halfway through what could be her final season with the show -- with an offer to reinstate her previous status as a full series regular. And apparently she's turned them down.

With A.J. Cook departing 'Criminal Minds,' the series is adding another female character: Rachel Nichols will join the cast for a three-episode story arc later this season.

According to Deadline Hollywood, Nichols will play FBI cadet Ashley Seager. Look for Agent Hotch to invite the young cadet to consult on a case because of her family history.

The role was originally conceived as a series regular part, but has since been downgraded.

In other casting news ...

• Catherine Dent will guest star on 'NCIS.' Dent will play a former NCIS agent who has a past with Ducky. Look for 'The Shield' alumna to appear in at least two episodes in November. [Ausiello Files]

• Anna Kournikova will appear on NBC's 'Biggest Loser' on Tue., Oct. 5. The tennis pro will put the remaining contestants through a workout challenge that turns into a battle of the sexes. [TV Guide]