'The Big Bang Theory' Season 10 air date, spoilers: Here's what we can expect from Penny's mom and brother

"The Big Bang Theory" is set to introduce Kaley Cuoco's character Penny's family members in Season 10. The role of Penny's mother will be essayed by "Sons of Anarchy" and "Married with Children" alum Katey Sagal while "30 Rock" alum Jack McBrayer will play Penny's brother, showrunner Steve Molaro revealed at Comic-Con.

Interestingly, this casting will be a reunion for Cuoco and Sagal, who acted together in "8 Simple Rules."

Penny's mom Susan is described as a stressed-out and neurotic person and McBrayer will play Randall, a cheerful former drug dealer and ex-con.

Something else that will be dealt with in Season 10 will be Penny's career. In the previous season, Penny revealed that she was unhappy in her job, but she was reluctant to leave it because she was making a lot of money. "We're still figuring things out; I think she's in an interesting and relatable place. She's going to start to weigh her options," Molaro said.

Molaro also teased that the B-movie Penny was a part of, "Serial Apist," has become so popular that it has now developed a cult following. She might be able to make a few money "signing autographs at small conventions as the star of 'Serial Apist'" in Season 10, the showrunner teased.

As for whether they have an endgame in mind, Molaro said that it was too soon to think about. "I'm not gonna tell you. There's been a few thoughts that have floated around, but we don't really know how long the show's going to go on for, so I think it's a little early for us to be thinking about an end point."

"The Big Bang Theory" will return to CBS on Sept. 19.