One of the biggest surprises in Avengers: Endgame was the revealing of Bruce Banner’s Smart/Professor Hulk early in the film. It turns out, the original plan was to unveil this version of the Hulk in the series’ previous entry, Avengers: Infinity War.
For the uninitiated, Mark Ruffalo’s Hulk was only on the screen for a minute or two in Infinity War, losing a fight to Thanos and retreating into Banner’s mind for the rest of the film. As this deleted scene shows, Smart Hulk was set to be introduced in the film’s third act right before things began to take a devastating twist.
I love Infinity War, but we deserved to see Smart Hulk’s transformation in the final film. pic.twitter.com/UnbAjH3lE0
— Borks and Beans | BLM (@bork_21) July 8, 2020
Banner would detail how he spent nearly two years in a lab merging his brain with the Hulk’s brawn in Endgame. The deleted scene rolling out the hyper-intelligent Hulk in the previous film can be seen in the Infinity Saga box set. Professor Hulk first debuted in Marvel Comics in the early 1990s.
In the end, it probably made the most sense to save the big reveal for the final film, rather than give Banner/Hulk an uplifting moment right before half the universe turned to dust in Infinity War.