Tom Cruise, Russell Crowe and Johnny Depp — all of them over 50 — represent the stars of Universal’s growing Monster Universe.

Not that there’s anything wrong with that.

Cruise and Crowe will star in “The Mummy,” in theaters next summer, and in the spring of 2018 Johnny Depp will lead “The Invisible Man.”

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Javier Bardem is the probable choice to play Frankenstein in the studio’s developing cinematic universe. He’s the youngest of the group at 47.

The ages of the stars have some industry experts scratching their heads over how Universal plans to keep attracting younger audiences — something the studio has done expertly with its hit “Despicable Me” series and billion-dollar-plus “Fast & Furious” franchise, not to mention its “Jurassic” series and “Pitch Perfect” movies.

Universal’s recent recruiting of aging stars and classic monster territory is even more perplexing given that studios like Sony place their tentpole bets on younger, rising stars, like Tom Holland as the new Spider-Man.

“I just hope they didn’t write big paychecks to these stars, as Johnny Depp and Javier Bardem aren’t necessarily box office draws,” argued Jeff Bock, senior analyst at Exhibitor Relations. “Tom Cruise, on the other hand is a big coup, as he still attracts wide swaths worldwide,” he said.

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He added a prediction: “‘The Mummy’ should do well, and adding Frankenstein and The Invisible Man for a ‘monster squad’ movie would be cool, if that is their eventual plan.”

Bardem’s casting doesn’t automatically mean a green light for a Frankenstein standalone movie or franchise, sources close to the project told TheWrap.

As “The Mummy” is the only Monster Universe movie to enter production so far, Universal’s eventual plan is still clearly a work in progress.

“The Mummy” does feature younger, buzzy cast members in Jake Johnson, of “Jurassic World” fame, and “Kingsman: The Secret Service” star Sofia Boutella — who is a hot property in Hollywood right now, with five upcoming projects including “Star Trek Beyond.”

And maybe that’s enough.

In Disney-Marvel’s wide-reaching “Avengers” franchise, Tony Stark is played by a 51-year-old Robert Downey Jr. But he started playing the superhero part nearly a decade ago when he was still in his early 40s. He has also indicated he may be done with the role, and it’s not yet clear whether he will appear in the two upcoming “Infinity War” movies. And there’s no “Iron Man” sequel on the horizon.

Moreover, the Iron Man actor shares the limelight with much younger castmates like Scarlett Johansson and Chris Evans. The expanding MCU now includes Chadwick Boseman as Black Panther and will soon expand to feature Oscar winner Brie Larson as Captain Marvel.

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So why create a pricey tentpole franchise around classic movie monsters played by middle-aged movie stars?

“There is no doubt Universal is banking on these classic headliners to reboot their classic monster movies,” said Bock.

The potential problem? “There hasn’t been a lot of demand to see these characters in some time.”

He argued that Universal needs another franchise outside of its “Fast & Furious” movies, its Illumination Entertainment animated features — including the studio’s most recent success with “The Secret Life of Pets” — and others previously mentioned in order to stay competitive.

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Warner Bros.’ recent weak opening for the very expensive “Tarzan” movie serves as the latest proof that dusty intellectual property isn’t necessarily playing to audiences these days. Tarzan is, after all, a century-old character.

“The Mummy” was first released by Universal in 1932 with Boris Karloff in the lead role. The studio also put out the first “Frankenstein” movie in 1931. In fact, said comScore’s Paul Dergarabedian, Universal’s long legacy of horror “is baked into their creative and corporate DNA.”

Moreover, Dergarabedian said Cruise, Depp, Crowe and Bardem have something in common with the stars from that bygone era: “Boris Karloff, Bela Lugosi and Claude Rains were themselves no spring chickens when they performed brilliantly in movies such as the original ‘Frankenstein,’ ‘The Mummy,’ ‘Dracula’ or ‘The Invisible Man.'”

Added the analyst: “Perhaps the older actors can bring a level of gravitis to these very meaty roles that perhaps a younger, less seasoned actor could not generate.”

The new vision for the cinematic universe should be a very modern reimagining. It is under the guidance of Monster Universe architects Alex Kurtzman — who wrote the first two “Star Trek” reboot installments and produced 2014’s “The Amazing Spider-Man” — and “Fast & Furious” series producer Chris Morgan.

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Lest we forget, Universal became the highest-grossing studio of all time last year in spite of the fact that it doesn’t have any major superhero properties as do Warner Bros. and Disney. But Universal is likely to lose the crown to Disney soon.

The studio could use an extra boost, as it holds only 10 percent of the box office market share in 2016 so far, behind Disney, Fox and Warner Bros. — which all have superhero franchises.