There's a good chance not everybody was familiar with Forest Whitaker's Saw Gerrera in Rogue One: A Star Wars Story, but he's actually been around for a little while. Before the rebel extremist played his part in securing the Death Star plans, he was seen in the awesome animated series, Star Wars: The Clone Wars, as a much younger man. And apparently he played a pretty big part in the events between the prequel trilogy and the original, because he's also appearing in the third season of Star Wars Rebels, and now we have a new trailer focusing on him.
Whitaker returns to voice Gerrera in the two-part storyline, "Ghosts of Genosis". This will help fill in the blanks on how he went from the hopeful young man we saw in 'The Clone Wars' to the battle-hardened extremist in 'Rogue One'. Otherwise it's pretty hard to reconcile the two, I think. This is one of the cool things about Disney's restructuring of the Star Wars continuity. It makes appearances like this so much easier to follow.
Star Wars Rebels returns January 7th.