"The Big Bang Theory" season 9 will see the return of Sheldon's mom Mary Cooper (Laurie Metcalf) and Penny's dad, Wyatt (Keith Carradine).
According to Entertainment Weekly, Mary will be part of the premiere episode of "The Big Bang Theory" entitled, "The Matrimony Momentum." Meanwhile, Penny's dad Wyatt will appear in the third episode of season 9.
In other news, showrunner Steve Molaro previously confirmed that Sheldon's alleged engagement ring will be discussed in season 9. Penny and Leonard's wedding will serve as the main storyline for "The Matrimony Momentum."
"The Big Bang Theory" star Kaley Cuoco-Sweeting recently spoke with Entertainment Tonight about the upcoming season of the hit CBS series.
Cuoco-Sweeting said that they already started filming season 9 and added that everything will be fun and exciting in the upcoming installment. The actress also said that all of her dreams came true in terms of Penny and Leonard's storyline. Whether or not this involves an onscreen wedding is something that fans need to watch out for.
"The Big Bang Theory" cast member Mayim Bialik also talked about the shocking split of Amy and Sheldon in season 8. The actress said that the entire cast was just as shocked as all the fans when Amy decided to end her relationship with Sheldon.
However, the couple could still reunite in the upcoming season especially since they have always been fond of each other.
"The Big Bang Theory" season 9 will premiere on CBS on Sept. 21 at 8 p.m. ET.