"Criminal Minds" season 11 is ready to debut on CBS on September 30 but the cast will no longer feature leads Kate Callahan and Jennifer Jareau.

Last season, Jennifer Love Hewitt's character Kate Callahan experienced a tough time, with her neice abducted and Kate just delivering her baby. She decided to take a break from the FBI's Behavioral Analyst Unit (BAU). The real reason for Hewitt's temporary exit is the birth of her new son. A.J. Cook's Jennifer Jareau will also be giving birth to another baby.

They will be replaced by fan favorites Paget Brewster, who will reprise her role as Emily Prentiss according to Movie News Guide. Aisha Tyler will also be joining the cast as Dr. Tara Lewis.

CrossMap gave a preview on what to expect from Tyler's character.

"Her dream was to study psychopaths up close and personal - and her psychology background, combined with her experience in the FBI, brought her face-to-face with monsters."

Series producer Erica Messer said that they are optimistic that both cast members will be back in the future.

"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," Messer told Entertainment Weekly.

She added that they are not actually replacing Hewitt and Cook, but introducing new characters gives them flexibility. She added that the writers are looking out for fans as they want to give them fresh look on the show, which is entering its 11th season.

She hinted that there might be new characters coming in that could change the landscape of the show.

"It's way more realistic for, after 10 years, people to have moved on or moved into a different division or something like that. It's such a rare thing to be in the same FBI unit for all those years," Messer added.

According to a report by Ecumenical News, "Criminal Minds" season 11 may only have 22 episodes, the least since its 2005 launch. Accordign to Master Herald, season 11 will be shortened to lessen the impact of cutting cast members, and does not mean that this will be the last season for the crime-oriented TV show as ratings remain strong.