'The Big Bang Theory' season 10 spoilers, plot news: Upcoming season to deal with Penny's big family issues

The upcoming tenth season of "The Big Bang Theory" will premiere on Sept. 19. The hit CBS sitcom will be looking back to the characters' past, as well as introducing new people dear to the series' lead players. According to the latest reports, the tenth season will be tackling mostly on Penny's (Kaley Cuoco) personal life, particularly her family issues.

"The Big Bang Theory" executive producer Steve Molaro revealed in an interview with Entertainment Weekly that Penny will have a lot of family problems to deal with in the upcoming season. One would expect that Season 10 will be centered on Penny's family as Keith Carradine, Katey Sagal and Jack McBrayer are all confirmed to play the roles Wyatt, Susan, and Randall, respectively. Wyatt is Penny's father, which was already featured in the earlier seasons of "The Big Bang Theory." Susan and Randall are Penny's mother and brother, respectively.

Sagal's character is described to be "neurotic" and "stressed out" as she has been living with Randall for a long time. Penny's brother is known to be a former drug dealer and ex-convict. Randall might be the source of Susan's hysteria, but he is shaped up to be a "cheerful" character.

According to Molaro, the very first episode of "The Big Bang Theory" Season 10 will be featuring the tensions between Susan and Randall. The fans will see how Penny is affected by Susan and Randall's frequent clash, and even his father is also caught in between the tension.

"Penny's close with her dad," said Molaro. "As we know, her brother Randall has been a bit of trouble over the years, selling drugs and being in and out of jail, and that's put a lot of stress on her mom."

E! News reported Sagal and Cuoco's appearance on "The Bang Theory" Season 10 as a mother and daughter tandem is not the first time. The two already worked together in ABC's past comedy TV series "8 Simple Rules for Dating My Teenage Daughter," where Sagal also appeared as the mom of Cuoco.

Aside from Cuoco, "The Big Bag Theory" Season 10 will also feature the return of main cast members Johnny Galecki, Jim Parsons, Simon Helberg, Kunal Nayyar, Mayim Bialik and Melissa Rauch. They are known to play the popular characters of Leonard Hofstadter, Sheldon Cooper, Howard Wolowitz, Raj Koothrappali, Amy Farrah Fowler and Bernadette Rostenkowski.