Jennifer Lopez Reveals Celebs Who Turned Down Cameo in 'This Is Me... Now'

Jennifer Lopez's new flick "This Is Me ... Now" is buzzin' with some major guest stars ... but it could've been a whole different ball game -- that's if some other big shots hadn't passed on it.

The star spilled the tea on the casting journey in her newly dropped Prime Video doc, "The Greatest Love Story Never Told" ... where she and her crew first reached out to big shots like Taylor Swift and Ariana Grande. But, Tay was busy with her "Eras" tour, and AG was filming "Wicked" over in London. Bummer!

That wasn't all ... Jason Momoa, Jennifer Coolidge, Lizzo, Vanessa Hudgens and even Snoop Dogg all passed 'cause they were unavailable.

And get this, Khloé Kardashian was supposed to pop in for a cameo, but she pulled out at the eleventh hour -- something J Lo chalked up to the reality star being scared to put herself out there.

SZA, Bad Bunny, and Anthony Ramos rounded out the list of A-listers who also passed. Imagine the star power if they'd all signed on!

But, J Lo's all about keeping it real ... and during a candid chat with her manager Benny Medina she acknowledged that no one wanted to turn her down ... but as someone who's been in the biz for a long time, she knows that people will pass on a project if they don't think the script is up to par. It's just how the game goes, and J Lo gets it.

But, J Lo didn't let those rejections get her down ... she bounced back big time by rounding up a stellar crew including Sofia Vergara, Jane Fonda and Trevor Noah.