Warning: SPOILERS for Avengers: Infinity War are ahead!
Although Bruce Banner, a.k.a. The Hulk, has been an important part of the Marvel Cinematic Universe since the year the franchise launched, unlike fellow founding Avengers Iron Man, Thor and Captain America, he never received a standalone sequel adventure due to Marvel having distribution issues with Universal. Since The Incredible Hulk's release, Mark Ruffalo has taken over the Banner/Hulk role from Edward Norton, and while the character has since appeared in all of the Avengers movies, Thor: Ragnarok and even the Iron Man 3 post-credits scene, The Incredible Hulk has barely been referenced, turning it into the black sheep of the MCU. However, with Avengers 4 serving as both the final installment of the Phase Three slate and the capper to Hulk's special trilogy that began with Thor: Ragnarok, the movie would be wise to directly acknowledge the events of The Incredible Hulk, preferably by bringing back some faces we haven't seen in a while.
Compared to later MCU movies, The Incredible Hulk felt more like a self-contained superhero movie, which was a lot easier back then, since it was only the second MCU movie to be released. That said, there were references to S.H.I.E.L.D. and the Super Soldier Serum program that gave Steve Rogers his enchanted abilities, and Tony Stark (Robert Downey Jr.) even popped in during the mid-credits scene to drive home that this existed in the same world as Iron Man. But since then, The Incredible Hulk has only been referenced/alluded to twice in the MCU movies.
First, Bruce Banner mentions to Tony Stark in The Avengers that it wouldn't be a good idea for him to visit Stark Tower since the last time he was in New York he "kind of broke Harlem," referring to his fight with Emil Blonsky, a.k.a. Abomination. Second, William Hurt reprised Thaddeus "Thunderbolt" Ross, who is now the U.S. Secretary of State, in both Captain America: Civil War and Avengers: Infinity War, but there's no mention in either movie of his personal vendetta against Hulk. Sure, there was that short film The Consultant that elaborated on The Incredible Hulk's mid-credits scene, and the Agents of S.H.I.E.L.D. TV series references Blonsky's imprisonment a few times, but the movies themselves have barely acknowledged its existence.
Fortunately, this hasn't prevented Bruce Banner/Hulk from being a compelling character in his subsequent MCU appearances, and Avengers: Infinity War served as the second chapter of this current Hulk trilogy that kicked off with Thor: Ragnarok, where when we reunited with him, Hulk had been behind the proverbial steering wheel in the whole two years that had passed since Avengers: Age of Ultron. After being brutally beaten by Thanos and subsequently transported to Earth by Heimdall, Hulk refused to come out for the rest of Infinity War, leaving Banner to fend for himself. Some fans had speculated that Hulk didn't reemerge because he was scared after receiving his thorough beatdown, but co-director Joe Russo noted that this twist also reflects Hulk being fed up with only being called out to get Banner out of jams.
In any case, Avengers 4 will conclude this three-part Hulk arc, and I doubt I'm alone in wondering if the movie's events will see Hulk operating with Bruce Banner's full intelligence. It hasn't been confirmed yet whether or not Mark Ruffalo will reprise Hulk/Banner in Phase Four, but whether this will be his last appearance or not, since Avengers 4 is going to be so important for the character, it's not enough to just highlight Hulk individually. The movie should also remember his MCU roots and call back to his debut in The Incredible Hulk. Like Avengers: Infinity War, Avengers 4 will have a packed plot, so we don't expect this to serve as an indirect Incredible Hulk 2, but it would be nice if we could follow up on Banner's life before he became one of Earth's Mightiest Heroes.
This could best be accomplished by bringing back one of The Incredible Hulk's main players, and no, another Thaddeus Ross appearance doesn't count. Abomination was imprisoned at the end of The Incredible Hulk, so maybe he's managed to escape in the aftermath of Avengers: Infinity War and is causing trouble. The last time we saw Samuel Sterns, his open head wound had been infected by Bruce Banner's blood, foreshadowing his transformation into The Leader. Since a new Hulk movie isn't on the horizon, it's highly unlikely we'll ever see a Hulk vs. Leader clash on the big screen, but it would be nice to learn what happened to Sterns. But perhaps the best course of action is to finally reunite Banner with Betty Ross, who, as far as we know, has seen him once over the last decade. No doubt Banner was originally keeping his distance from Betty to keep her safe, but considering how important she was to him once upon a time, it's somewhat ridiculous that he hasn't maintained any communication with her. Let's resolve this romantic relationship properly. Better late than never!
If Avengers 4 does end up being Bruce Banner/Hulk's last MCU appearance, it's only appropriate that a little time is dedicated to honoring the story that introduced the character to this franchise. The Incredible Hulk may not be the most popular MCU movie, but it was nonetheless an important chapter. From what little we've learned, Avengers 4 has big things in store for Hulk, so along with that tremendous character development, it makes sense to tie that in with his only standalone MCU movie, preferably by bringing back one of those supporting characters (seriously, please let it be Betty). Hulk has a rich mythos in the comics, and while it may never be possible to fully explore it in the MCU given legal entanglements, the least the Marvel bigwigs could do is touch upon what was set up in The Incredible Hulk during next year's movie.
Avengers 4 opens in theaters on May 3, 2019, but you can watch Hulk and his fellow MCU heroes battle Thanos and his monstrous hordes in Avengers: Infinity War now. Stay tuned to CinemaBlend for all the biggest updates concerning the MCU.