Bruce Banner, the brilliant physicist who merged his mind with the Hulk's body to become Smart Hulk in Avengers: Endgame, is back in Spider-Man: Brand New Day, and he does not look anything like the massive green Avenger fans last saw in She-Hulk: Attorney at Law. In that Disney+ series, Banner was in full Smart Hulk form, having permanently fused his two personalities together. Walking into a Spider-Man film looking like an ordinary professor was expected, thanks to set photos that surfaced from the film's shooting. However, it was not really clear why Banner was in human form.
The official trailer for Spider-Man: Brand New Day, released March 18, confirms why. Mark Ruffalo's Bruce Banner appears in the footage fully human, wearing regular clothes and teaching a class at what appears to be Empire State University, and, crucially, a small device is visible on his right wrist.
That device is the Hulk Inhibitor, a piece of technology he first wore in the Shang-Chi post-credits scene. In that scene, he appeared alongside Carol Danvers in human form with his injured arm in a sling, an arm he had damaged using the Infinity Stones in Endgame. He later appeared with it in She-Hulk: Attorney at Law. Its presence on Banner's wrist in the new trailer explains how he shed his Smart Hulk form ahead of his Brand New Day appearance.
The Hulk Inhibitor Device is a prototype Banner engineered himself, designed specifically to suppress the gamma radiation in his body and allow him to revert to human form. The inhibitor allowed his human body to heal the injury that his Hulk form was preventing it from recovering properly.
When it reappeared at the start of She-Hulk, Banner explained to his cousin, Jennifer Walters, during a road trip that he created it because, after achieving his Smart Hulk form, he had lost the natural ability to transform back. The Hulk merger was permanent, and the only way to return to his human body was the device.
The device, however, did not last. During that road trip, a Sakaaran spacecraft suddenly appeared on the road, causing a car crash. The impact destroyed the inhibitor. Banner reverted to Smart Hulk, and in the chaos, his gamma-irradiated blood entered Jen's bloodstream, transforming her into She-Hulk.
The version Banner wears in the Brand New Day trailer is not the same as the one that broke. The original had a gauntlet shape fitted to his left arm. What Banner sports in the new footage is a noticeably smaller, redesigned unit on his right wrist. So it's obvious he went back to the lab to reengineer this version in between the events of She-Hulk and Brand New Day.
How Big Will Bruce Banner’s Impact Be in Spider-Man 4?
How long Banner has the inhibitor on in Brand New Day will be interesting to see, but it’s pretty obvious he's going to play a big role. The trailer shows him living quietly as a civilian, teaching, with no visible signs of distress. Banner obviously enjoys the normalcy and the clear mind he has, but all that could change as the film progresses.
Peter comes to him with a crisis as his DNA is mutating in dangerous ways, and that kind of pressure has a way of pulling Banner back into the chaos. The more entangled he gets in Peter's situation, the higher the chances of unexpected drama interrupting his peaceful life. When that happens, it brings his big green friend into the fold, too.
He enters Brand New Day as a scientist trying to help, but the film's threats are stacking up fast. The trailer shows the Hand, a ruthless ninja organization, converging on Peter and Damage Control as they get involved in the chaos. Peter will obviously be in so many life-threatening situations in this film. So, he's going to need all the help he can get.
Bruce is likely to aid Peter beyond the nerdy stuff and be an ally on the battlefield. There's also the possibility that he's the opposite. If Hulk spirals out of control, he'd need someone to stop him, and that person is likely to be Peter. Whatever the case may be, Banner's role in Brand New Day will be huge in both human form and Hulk form.
Geraldo Amartey is a writer at The Direct. He joined the team in 2025, bringing with him four years of experience covering entertainment news, pop culture, and fan-favorite franchises for sites like YEN, Briefly and Tuko.
