Fans of 'Criminal Minds' will miss two vital characters of the show when the police procedural television series on CBS returns for Season 11 on Sept. 30. Two members of the Behavioral Analysis Unit (BAU) team Kate Callahan (Jennifer Love Hewitt) and Jennifer Jareau (AJ Cook) will not be featuring in the upcoming season of the show owing to their respective pregnancies. However, Aisha Tyler will replace Callahan, who seems to have left the show for good, while Hewitt spot has been left open, as she is expected to return after the first five episodes.

Citing a report in Entertainment Weekly, IB Times states that Tyler came on-board following Hewitt's departure and is likely to replace Kate Callahan's character Dr Tara Lewis.

According to EW, right at the beginning of the premiere episode of 'Criminal Minds' Season 11, fans will see Aaron Hotchner (Thomas Gibson) interviewing several candidates for Kate's position and Dr Lewis, a psychologist with an interest in forensic psychology and its application in the criminal justice system, proves to be the most suited candidate to join the BAU team.

As of now, it is unclear if Hewitt, who welcomed a baby boy recently, will come back. However, in an interview with EW, showrunner Erica Messer said that the spot is being left open in case the actress decides to return.

According to Messer, in case Jennifer decides to return, the writing team can always work out a plan to reintroduce her in the show.

Messer told the website, "You always have a place here, and we believe that wholeheartedly off-screen as well. One of the great things about our show is you can leave those doors open. We rarely kill anyone. That opportunity for paths to cross again is definitely open."

Fans of 'Criminal Minds' will now have to wait and see if Aisha Tyler's Dr Tara Lewis is capable of filling in the void created by Jennifer Love Hewitt's exit, albeit temporarily, from the show.

'Criminal Minds' Season 11 will premiere on Wednesday, Sept. 30 on CBS.