"Percy Jackson & the Olympians: The Lightning Thief" actor Jake Abel has joined the cast of "I Am Number Four," director D.J. Caruso's adaptation of James Frey and Jobie Hughes' forthcoming science-fiction novel of the same name, MTV News has learned exclusively.

The sci-fi story focuses on nine aliens who survive the destruction of their home world at the hands of a ruthless rival species. The survivors flee to Earth and blend into their human surroundings in order to hide from the aliens who continue to hunt them. Abel will play Mark James, a high school football player who sees a social threat in Number Four, the young protagonist and new kid in school played by "Beastly" actor Alex Pettyfer.

"Mark is a football player at the school and he's skeptical of the new kid because he's trying to move in on his ex-girlfriend," Abel told MTV News in an exclusive interview. "He's the high school jock who's just loaded with insecurities. He masks them with his bravado and intimidation, but he's threatened because this new kid is coming to school and there's a lot of attention on him. A lot is happening around him."

Despite his experience as the villainous Luke Castellan in "Percy Jackson," Abel's antagonizing ways won't intersect too heavily with the overarching sci-fi story of "I Am Number Four."

"Unfortunately, I'm not really getting involved with all of the crazy sci-fi stuff," said the actor. "In a previous draft, there was a big fight scene that Mark was a part of and I was stoked for it. It was so wicked. Then I got a new rewrite, and suddenly Mark wasn't in a fight anymore. I was really kind of bummed by that. It would have been a lot of fun!"

That doesn't mean Abel isn't getting physical for the role. The actor revealed that he's currently on a rigorous workout campaign to get into the kind of shape his football-playing character should be in.

"Kind of at the last minute, D.J. Caruso reached out to me and said, 'I want you to get big.' So now they've got me [working with] a trainer, and now every day has been nothing but eating and lifting weights," he laughed. "Luckily, he's a quarterback, so he doesn't have to be huge!"

He'll have to get into that idealized shape quickly, as Abel said he begins filming his role on June 9. Asked what he found the most appealing about "I Am Number Four," the actor revealed: "What attracted me to it was D.J. Caruso, hands down. That's what really made me want to do this. I think he's really talented and has potential to be phenomenal. When we did the reading process for the audition, the notes that he gave me, we kind of spoke the same language. I'm really excited to see how he handles the situation on set."

Abel joins a growing cast, including the previously mentioned Pettyfer as Number Four, Timothy Olyphant as his guardian Henri, Teresa Palmer as the alluring Number Six and Kevin Durand as an alien antagonist.

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