According to a recent report by Deadline, Stranger Things star Sadie Sink has joined the cast of the next Avengers movie. The teen actress will return to her breakthrough role of Max Mayfield in the final chapter of the Duffer Brothers' sci-fi series on Netflix, following which, Sink is eyeing a role in the MCU.While the actress had officially joined the MCU with her casting in Tom Holland's upcoming movie, Spider-Man: Brand New Day, her alleged role in the next Avengers movie hints at her larger role in the beloved franchise. Since the upcoming Spider-Man movie has kept Sadie Sink's character a mystery, it is difficult to predict how she will contribute to the upcoming project.Since Robert Downey Jr.'s first stint in Doomsday has officially wrapped filming, Sadie Sink will likely join the next project in line, Avengers: Secret Wars. While the Deadline report does not include many details about Sink's casting, it is revealed that the actress will begin shooting for the project in London later in 2026.More on this in our story.Sadie Sink has reportedly joined Avengers: Secret Wars View this post on Instagram Instagram PostSadie Sink fans are certainly eyeing the actress' MCU debut with Spider-Man: Brand New Day, which is scheduled for a July 31 premiere. To add to this fan excitement, multiple reports suggest that the Stranger Things actress has signed another Avengers film.Secret Wars, which will allegedly open in late 2027, marks the concluding chapter in the MCU's Phase Six and a direct follow-up to Doomsday. While the plot details for the movie are being kept under wraps, the movie will feature Robert Downey Jr.'s Doctor Doom and many veteran MCU stars. It is also known that Secret Wars will be directed by the Russo brothers and will feature an important storyline from the comics, which includes a 'reset' of the multiverse.Sadie Sink's involvement with Avengers: Secret Wars certainly opens doors to new possibilities. While fans are already speculating about the Stranger Things star's character in Brand New Day, it could have direct ties to the upcoming Avengers movie.A popular fan theory suggests that Sink will play a variation of Mayday Parker, Peter Parker and Mary Jane's daughter, in Spider-Man: Brand New Day. While it is difficult to establish Mayday's ties with Holland's superhero, the character somehow fits in Secret Wars' narrative. As Tobey Maguire's Peter's daughter, Mayday, could join forces with Holland's superhero to put an end to the evil Doctor Doom.While the possibilities are endless, Sink's role in the MCU still remains a mystery. The Brand New Day premiere could clear some air about the actress' future in the franchise, but fans will have to wait for that.However, before her highly anticipated debut in the MCU, Sadie Sink will return to her iconic character of Max to fight against Vecna with her friends in Stranger Things Season 5.For the latest scoops on your favorite TV shows and movies, follow SoapCentral.