According to Deadline, Aguilera and Green both left the the reality competition to concentrate on their individual music projects. Aguilera needed to promote her album, "Lotus," while Green wanted to focus on his Loberace Las Vegas show.
Reports said that the 32-year-old Aguilera had already signed a fifth-season contract for $12.5, million, though she earned $17 million for season three. According to the Wrap, Aguilera could earn up to that much money again, since "The Voice" coaches are paid by the hour. Meanwhile, the 38-year-old Green is currently "in advanced negotiations" about his return to the show.
Executive producer Mark Burnett told The Hollywood Reporter last year that the revolving judges line-up isn't surprising.
“These are current touring artists, so it’s a matter of balancing schedules. They’re all in demand, and we’re just balancing it all," he said.