Avengers: Infinity War is set to be the biggest Marvel flick to date, bringing almost all of the superheroes together on the big screen for a first confrontation with Thanos. It will also be when we finally find out what the Mad Titan's endgame is and where the three Marvel Phases have led. So it will be a big film - fortunately, the Russos will direct it, after meeting huge success with both Captain America: The Winter Soldier and Captain America: Civil War.
And since there weren't that many characters for the directors to juggle, two more have been announced. The first one is Maria Hill, who was last seen running the Avengers facility at the end of Avengers: Age of Ultron. The announcement was made by actress Cobie Smulders, during an interview with Jimmy Kimmel. You can check it out below.
https://www.youtube.com/watch?v=vV0UGoEBY8I
It made sense for her to appear in the Infinity War, given the role she took at the end of Age of Ultron.
The other confirmed character is also a supporting one. However, unlike Maria Hill (who had appeared in both of the Avengers movies to date), he hasn't been seen just yet by US audiences. He is Wong, and is set to debut in Doctor Strange on the 4th of November.
During an interview with Comic Book, actor Benedict Wong said that he is thrilled to join the expanding cast of Avengers: Infinity War. Given his role as a mentor to Steven Strange, it makes sense to see him at the Sorcerer Supreme's side in the hardest of all battles.
But, as with Maria Hill, it isn't known how much screen time he will have.