It turns out that Hulk's arc between Infinity War and Avengers: Endgame was originally quite a bit different than what we ended up with. Writers Christopher Markus and Stephen McFeely, who have been on this ride with directors Joe Russo and Anthony Russo from the beginning, recently gave an in-depth interview, answering a great many questions fans may have had after seeing the movie this weekend. And what they had to say about Mark Ruffalo's Bruce Banner/Hulk is particularly interesting.

Warning: spoilers ahead for Avengers: Endgame. Last chance to turn back. As fans will surely recall, Hulk and Banner weren't exactly getting along of their encounter with Thanos at the beginning of Infinity War. As such, Hulk took a backseat for the rest of the movie, leaving Banner to fight in the Hulkbuster armor. When we catch up with him in Avengers: Endgame, he's become "Professor Hulk," after spending months in a lab reconciling the best parts of both Banner and Hulk into one. However, as Marks and McFeely revealed in the interview, this change was supposed to happen much sooner. Here's how the broke it down.

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Markus: There was a time when Banner became Smart Hulk in the first movie. It was a lot of fun, but it came at the wrong moment. It was an up, right when everyone else was down.

McFeely: It happened in Wakanda. His arc was designed like, I'm not getting along with the Hulk, the Hulk won't come out. And then they compromise and become Smart Hulk.

Markus: We were like, but he's Smart Hulk in the next movie. So that diner scene [in "Endgame"], was like, O.K., how do we smash right into that without scenes of him in a lab, gene-splicing?

McFeely: Oh, I wrote scenes in a lab. Now it's just him eating pancakes and I think it generally works.

Markus: The whole thing rides on Rudd going, "I'm so confused."

Professor Hulk is first encountered at a restaurant and there is really no set up for it. But in the context of the movie, it works quite well and actually provides one of the best bits of comedy in the three-hour runtime. Ultimately, the arc, as is, worked out quite well and it's probably best that they saved the surprise for after Infinity War.

The question is, at what point in the process did this change? Pretty famously, there is a scene from the Infinity War trailer with Hulk alongside the rest of the heroes in Wakanda getting ready to do battle against Thanos' army. That ended up not making it into the movie. Some wrote this off as a misdirect, but it's possible, at that point, they still were going to go the Professor Hulk route.

Things, as they are, are hard to argue against. Infinity War grossed more than $2 billion worldwide and Avengers: Endgame is already well on its way to that mark, if not on its way to becoming the highest-grossing movie of all time. Not to say this change would have dampened either movie's earning potential. Still, the results being what they are, it seems everyone made the right call. This news was first reported by the New York Times.