'Black Panther: Wakanda Forever' "saved a space" for Chadwick Boseman on the call sheet.
The late actor died of cancer in August 2020, before work began on the film, but bosses on the upcoming sequel refused to put any of his co-stars in the top slot on information documents because he will always be a part of the project.
Chadwick's co-star Winston Duke made the revelation while reflect on how "hard" it was working without his friend.
He said: "It's really hard, but I don't think he's not with us.
"His efforts and his work and his legacy is with us. We carry him with us in our hearts.
"On set, we never had a number one on the call sheet. It started at number two because, Chadwick, we saved a space for him the entire time.
"I always say that in death, the struggle is finding ways to hold onto people. In life, it's how to let go of people, whether they're good for you or not. In death, it's how do you hold on, and we hold onto him in our hearts, in our work, in how we approach life moving forward."
The 35-year-old actor's mother passed away three weeks ago and Winston reflected on the ties between grief and the loss superheroes often suffer, admitting he thinks that's why comic book tales are so relatable.
He grew emotional as he told 'Entertainment Tonight': "I've realised in suffering a lot of loss myself, losing Chadwick, losing my mother maybe 20 days ago or so, I realise how intimately tied the narrative of superheroes and grief is.
"And that's what really makes them strong and relatable and powerful. Who is Spider-Man without Uncle Ben? Who is Batman without his parents? Who is Superman without all of Krypton?
"It's about loss and the triumph of coming through that."