"There is definitely some kind of work towards that," the Justice League star told MTV at CinemaCon in Las Vegas. "There's a lot of things spinning around in the universe right now with that."
"Obviously if Black Adam does become a character officially, he will play him," Cavill said of the Jumanji and Rampage star, who is gearing up to bring the ancient super-powered Egyptian prince to the shared DC Extended Universe.
The two titans might clash eventually, but likely not before Black Adam faces off against archfoe Shazam (Zachary Levi).
"I'm pretty sure it'll be a Shazam/Black Adam thing first," Cavill said. "If it does happen, it would make sense that way."
He continued: "But you never know, maybe there will be a Superman movie and Shazam will come and help. That's kind of stealing his limelight, though, which is not cool."
Johnson will executive produce his foray into the superhero genre under his Seven Bucks Productions banner with producing partners Dany Garcia, Hiram Garcia, Christopher Godsick, and Jeffrey Chernov.
Levi's beefy superhero makes his big screen debut in Shazam!, out next April, as studio Warner Bros. readies Johnson solo vehicle Black Adam.
"I think they've got a great plan over there with him and I wish those guys the best of luck," Johnson told ComicBook.com of the team bringing together Shazam's standalone, which pits the superhero against Doctor Sivana (Mark Strong) instead of arch-nemesis Black Adam.
"We had to split the idea because the obvious idea was Black Adam and Shazam," Johnson told us. "So we split it. Those guys are gonna do great with it."
In November, Johnson announced he was "excited to expand the DC Universe" with Rampage co-writer Adam Sztykiel and is ready to "bring this complex & gritty anti-hero to the big screen."
Johnson got in on the Superman vs. Black Adam fun in December 2016 when he shared fan art depicting the sometimes villain, sometimes anti-hero seated on a throne after whooping Superman's ass.
Rampage is now playing. Johnson's next big one, Skyscraper, opens July 13. Cavill will next be seen alongside Tom Cruise in Mission: Impossible – Fallout, in theaters July 27.
Shazam! opens April 5, 2019.