As it turns out, that goes double for the (literally) biggest Avenger of them all. Mark Ruffalo recently opened up at the D23 Expo in Anaheim, California and admitted that some significant changes are on the horizon for Hulk between now and the events of the fourth Avengers film, saying:
There's a huge change for Banner and for Hulk. It isn't resolved in the first Infinity War, it sort of culminates into the second Infinity War. Thor 3 is the beginning of a lot of changes for Banner and for Hulk.
It doesn't seem like a spoiler for Mark Ruffalo to admit that he will appear in Avengers 4. Bruce Banner is easily the most formidable member of The Avengers roster, and he seems to have the highest odds of survival when Thanos (Josh Brolin) finally comes to town. That said, we can now confirm that the arrival of The Mad Titan will alter this not-so-jolly green giant in some massive ways.Read more at HollywoodReporter