"Star Wars Rebels" season 2 began introducing characters from "Star Wars: The Clone Wars" and the older "Star Wars" movies, but according to a report from Movie Fone, it is possible that season 3 will introduce characters or events that will play a role in "Rogue One: A Star Wars Story" or other future films in the franchise.

"So it's trying to balance the two different things, like the original cast from the first season with 'Clone Wars,' with characters from the original movies, and maybe even feeding into future movies," explained executive producer Simon Kinberg.

Kinberg also explained that with the past seasons, they introduced characters from the older films and TV shows not only to allow the show to have a stronger connection to the franchise but to build up the core cast of "Star Wars Rebels," particularly the crew of the Ghost space ship. 

According to a report from Cinema Blend, it is possible that "Star Wars Rebels" season 3 will introduce a new crewmember that may make an appearance in "Rogue One: A Star Wars Story" given that the show focuses on the early stages of the rebellion against the Empire and that the film focuses on these rebels securing the Death Star plans.

It is also noted something similar has already been done as Forest Whitaker's character in the film, Saw Gerrera, was initially introduced in "Star Wars: The Clone Wars." 

It is also possible that season 3 may introduce a character that will be featured in "Star Wars: Episode VIII" or "Episode IX" but this is less likely to be true given that the newer films and the "Rebels" series take place roughly 30 years apart. 

"Star Wars Rebels" will be released later this year, although a specific launch date has yet to be announced. It will launch before "Rogue One" premieres in theaters, and therefore there is still time for the show to introduce a character that will be fleshed out more in the films.