The thesp will play Jose, Anastasia Steele's close friend from college and romantic rival of billionaire protagonist Christian Grey.
Along with HBO's "America," Rasuk is known for roles in "Raising Victor Vargas," Steven Soderbergh's "Che," "Lords of Dogtown" and, most recently, "Jobs." He will also appear in next year's "Godzilla."
Sam Taylor-Johnson is helming the pic, produced by Michael De Luca and Dana Brunetti. Kelly Marcel penned the script.
Variety previously broke the news that Jamie Dornan will play Grey after Charlie Hunnam dropped out of the film. Dakota Johnson is still set to play Steele. Other supporting roles have gone to Luke Grimes and Jennifer Ehle.
Rasuk is repped by Brad Lefler at Gersh, manager Katherine Atkinson at WSA and attorney Todd Rubenstein.
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