Milian will play Shawnee Baker, a successful pop star suffering from unusual symptoms in the installment, which will be directed by recurring guest star Eriq La Salle, the network said.
"We're thrilled that Christina will be bringing her acting and singing talents to 'A Gifted Man,'" executive producer Neal Baer said in a statement. "She'll play a spoiled pop star who complains of a mysterious ailment zapping all her energy that even Dr. Michael Holt finds puzzling."
This episode also marks of the reunion of "ER" alums LaSalle and Michael Beach, who plays Shawnee's manager.
Milian has appeared in the feature films "Love Don't Cost a Thing," "Be Cool," "Pulse" and "Ghosts of Girlfriends Past," as well as TV's "CSI: Crime Scene Investigation."
"A Gifted Man" stars Patrick Wilson as Holt. The cast also includes Jennifer Ehle, Margo Martindale, Rachelle Lefevre, Pablo Schreiber and Rhys Coiro.