"The Big Bang Theory" season 10 is going to be bringing in the parents of the main characters, and as reported by Entertainment Weekly, fans will finally get to meet Penny's (Kaley Cuoco) brother and her mother. Penny's father, Wyatt (Keith Carradine), had been introduced in previous seasons.

Her brother Randall will be played by Jack McBryer while her mother will be played by "Sons of Anarchy" and "Married with Children" veteran star Katey Sagal. According to Executive Producer Steve Molaro, both characters will be causing some trouble for Penny and Leonard (Johnny Galecki), who just got married in season 9.

In particular, Molaro explained that Penny and her father are very close and this has been portrayed in the past. The two will get caught in the crossfire between the drama of Randall and Penny's mother.

"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. You will pick up on the tensions between her mother and her brother very quickly, and you get a glimpse of Penny and her dad being caught in the middle of that," Molaro explained.

Cinema Blend reports that it is possible Penny and her father got close due to the fact that Penny's mother had to focus most of her time and attention on Randall given he was always in jail. It is speculated that season 10 will see Randall and his mother bicker with Penny and their father trying to calm the flames.

The report further points out that this will add to the chaos already started when season 9 ended when Sheldon's (Jim Parsons) mother and Leonard's father got together for what may be the beginning of a longer relationship. Fans speculate this may lead to the two getting married, making Leonard and Sheldon brothers.

"The Big Bang Theory" season 10 will premiere on Sept. 19.