• "Gladiator II" introduces Paul Mescal as Lucius, the son of Maximus (Russell Crowe).
• In the original "Gladiator" movie, the younger Lucius was played by Spencer Treat Clark.
• Here's why Clark doesn't reprise the role in "Gladiator II."

"Gladiator II" finally arrived on November 22, but fans are still wondering why Paul Mescal plays the slave fighter Lucius, instead of Spencer Treat Clark, who played him in the original movie.

Ridley Scott's "Gladiator" starred Russell Crowe as Maximus Decimus Meridius, a former Roman general who is betrayed and sold into slavery. Lucius, the heir to the Roman Empire, watches Maximus fight in the Colosseum.

Lucius disappeared after the events of the original movie and forged a new life for himself. But like Maximus, he's forced into becoming a fighter when he's captured by General Marcus Acacius (Pedro Pascal) and his soldiers.

It's not surprising that Scott cast Mescal as Lucius for the sequel considering the Irish actor has become a rising star after his critically acclaimed performances in"Normal People," "Aftersun," and "All of Us Strangers."

But "Gladiator" fans on social media have said it's odd that Scott didn't ask Clark to reprise the role since he's still working as an actor.

Scott said he needed someone younger to play Lucius in "Gladiator II"

Clark, who is now 36 years old, also played Joseph Dunn in "Unbreakable" opposite Bruce Willis — a role he later reprised in 2019's "Glass." And he's appeared in several TV shows, including "Agents of S.H.I.E.L.D," "Animal Kingdom," and "Manhunt."

Last November, Scott told Deadline that he wanted to cast a younger actor to play Lucius in "Gladiator II" and that he was impressed by Mescal, who is 28, in "Normal People."

"I'm always looking for someone, something new and fresh. I mean, fresh is terribly important," Scott said. "So they're not carrying … baggage is a terrible word for what they've done before, because it's great stuff, but you will remember he just did this character already.

"I watched this show called 'Normal People.' It's unusual for me, but I saw one and thought, that's interesting. These actors are really good I watched the whole goddamn show and thought, damn."

He added, "So this came up at a time when I need a 23-year-old, 24-year-old to take up the mantle of Lucius. And I just said, 'You want to do it?' He said, 'Yeah.'"

Spencer Treat Clark says he's "excited" to see "Gladiator II"

Speaking to People ahead of the HBO Max horror remake, "Salem's Lot," Clark explained that he holds no ill will against Scott or Mescal for replacing him as Lucius in "Gladiator II.

"The movie looks so good, and Paul's going to do such a great job. I've actually heard great things about the movie... I feel like it was 25 years ago, but for some people, seeing me as an adult and being like, 'Oh my God, you're right. You were Lucius in Gladiator,' is so wild," He said.

"But I'm really excited to see the movie and to see what Paul brings to it. And yeah, it comes out soon. So I'm excited for it."