A third Mamma Mia! movie is officially happening though its not in production yet and the plot for that project still remains under wraps. But that isn't stopping Amanda Seyfried from ruminating on ideas for who she'd want to star with her in the next installment. In the past, Seyfried who costarred with Meryl Streep in the 2008 musical film and its 2018 sequel, Mamma Mia! Here We Go Again in a leading part, Sophie brought up pop star Sabrina Carpenter as a potential name to appear in a new production inspired by the hit ABBA jukebox musical. At the Governor Awards on Sunday, the Mean Girls star added Sydney Sweeney's name to the mix when she was asked about Mamma Mia 3. See on Instagram There's been some fan speculation that Carpenter, 26, might play the daughter of Seyfried, 39. But in an interview with Entertainment Tonight, Seyfried said that she could see the "Please Please Please" singer as a different family member. "I love portraying a mom, so I would love to see Sophie with her kids," the actress said. "Maybe she has a cousin she hasnt seen in a while, and that could be Sabrina Carpenter. And then Sydney Sweeney could show up. Theres a bunch of girls that really want to be a part of it, and Im all for it.The details of the script, which producer Judy Craymer has confirmed exists, are being kept under lock and key. However, Seyfried gave fans a few hints for what they could maybe expect from the third movie. "I just know the three dads are going to come back, and we still wont know who the dad is because it doesnt matter. Meryl [Streep] is a ghost, obviously, so shell be around," she continued. "And Julie [Walters] and Christine [Baranski] will be back singing and looking hot and were all going to be somewhere tropical. And ABBA will be playing.The team is still remaining tight-lipped about what to expect in terms of a release timeline and when production could be expected to begin.Seyfried's remarks come in the wake of a series of box-office flops for Sweeney, whose film Christy, a biopic about the queer boxer Christy Martin, made headlines last week for its dismal numbers. Ruby Rose, who was up for the part, even said Sweeney "ruined" the production in the wake of controversy caused by an American Eagle ad, in which the Euphoria star was lauded for her "great jeans." The ad became a flashpoint in the culture wars, with some critics saying it smacked of eugenics and President Trump praising it. Sweeney's refusal to directly address the controversy in interviews has also sparked public frustration.