'Mufasa' Actor Braelyn Rankins Didn't Know Full Cast Until Trailer Dropped

The star of "Mufasa: The Lion King" says he didn't know who most of his other costars were until earlier this year ... though he always figured the script would attract massive stars.

Braelyn Rankins -- voice of young Mufasa in the upcoming Disney "The Lion King" prequel -- was on "TMZ Live" for an interview Thursday ... and, he tells us he only knew limited information about the movie when he was filming his part.

Rankins tells us that -- outside of the actors he personally worked with -- he had no idea who would be in the film ... so no indication he would star alongside Beyoncé, her daughter Blue Ivy, Thandiwe Newton or the like.

Braelyn says he read parts of the script and kinda figured big names like Bey would return -- reprising her role as Nala from the live-action 'Lion King' movie ... but, it wasn't until the trailer came out in April that his suspicions were confirmed.

'Mufasa' has been a long process for Rankins ... who first auditioned for the film back in 2020 and finally got to see the movie on two separate occasions recently.

Braelyn says he never saw a full script while recording ... so actually seeing the movie all the way through shed some light on some of the finer plot details.

Braelyn plays young Mufasa in the movie ... 'Lion King' main character Simba's father -- voiced by the late, great James Earl Jones in the original animated film and the 2019 live-action flick. Braelyn's sister Brielle also provided some lines for the character.

Aaron Pierre plays the older version of the character ... while Kelvin Harrison Jr., Blue Ivy Carter, Mads Mikkelsen, Seth Rogen, Billy Eichner, Keith David, Donald Glover and more have parts in the movie.

"Mufasa: The Lion King" comes out in theaters tomorrow, December 20.