"Criminal Minds" is set to return this fall for its eleventh run on the small screen. The police drama is going to bring avid viewers once more a treat as the FBI's Behavioral Analysis Unit (BAU) takes on new cases and challenges. There may have been a lot of changes in the longest-running police series thus far, but CBS can guarantee fans that the remarkable and familiar elements of the series will remain. Below are three things fans can expect when "Criminal Minds" season 11 airs this fall.

1. The absence of Agent Kate Callahan and Agent Jennifer "JJ" Jareau

After joining the show last season, Jennifer Love Hewitt is taking some time off this season as she has decided to focus on her mommy duties with her new bundle of joy. Early this year, show exec Erica Messer already confirmed the absence of the actress this season, as per Latin Post.

On the other hand, Hewitt isn't the only one who opted to do some mommy duties instead of filming for the show this season. Actress A.J. Cook, who plays Agent Jennifer "JJ" Jareau is also going to be "missing in action" for the first couple of episodes due to maternity leave. Fortunately, she'll be back halfway through the season.

2. The arrival of Dr, Tara Lewis

Since Kate is not around this season, the BAU team will be considering a few candidates to fill in for her. One of the candidates is Dr. Tara Lewis, a forensic psychologist who is very eager to join the team. International Business Times has learned that actress Aisha Tyler has been cast to play the part.

Meanwhile, former "Criminal Minds" actress Paget Brewster has expressed her desire to come back after being on the show for the first six seasons and leaving the series in season 7.

The "Grandfathered" star who is a close friend of A.J. Cook was quoted as saying by Zap2It: "I was hoping to jump in and do a couple [of episodes], because my friend A.J. Cook, who plays JJ, is [on maternity leave]. [Cook] called me and I said, 'I think [I can return], if we aren't doing 'Grandfathered' because I didn't know yet if we were picked up, and i didn't know what the schedule would be. It didn't work out this time, which is too bad because I love those guys."

3. The exit episode of one of the team members

Actor Matthew Gray Gubler, who plays Dr. Spencer Reid, is taking over the director's chair in one special episode where fans would see the exit of a still unnamed character. Speaking of the exit episode, Gubler says, "I am [directing]. There's a special episode. I almost don't want to give it away, but I might as well. It's the departure of one of the regular team members."

Gubler also expressed his desire for his character to grow this season, International Business Times has learned. "That's the great thing about playing a character for so long is that there's always new territory. Trying to take him a little bit more - I've always wanted him to show growth. I want to see him slowly become less socially awkward and more confident," Gubler said.

"Criminal Minds" is returning to the small screen this fall on Sept. 30.