New characters will be joining Season 11 of CBS' "Criminal Minds" with the exit of Kate Callahan (Jennifer Love Hewitt) and Jennifer Jareau (A.J. Cook).

The police procedural series, which is slated to air Sept. 30, will feature Aisha Tyler as Dr. Tara Lewis. She will be replacing Kate on the FBI's Behavioral Analyst Unit (BAU) after the undercover agent took a break from her work. Kate experienced a tough time last season, when her niece was abducted while she just gave birth.

Lewis is described as "a psychologist with an eye for forensic psychology and its application toward the criminal justice system." CrossMap gave a preview on what to expect from Tyler's character, saying that it was her dream to "study psychopaths up close and personal."

Hewitt and Cook are on a "temporary break" from the show as they will be both giving birth. Although still unclear when they will be returning, series Producer Erica Messer said the doors remained open for the two actresses.

In an interview with Entertainment Weekly, Messer said that the cast and crew remained optimistic that the characters f Kate and Jennifer would return 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."

The showrunner also said Hewitt and Cook were not being replaced, but new characters were being introduced to give the fans a "fresh look on the show." She even hinted that these new additions could change the "landscape" of the new season.

"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 said.

Season 11 of "Criminal Minds" premieres Sept. 30 on CBS.