On the show, the 40-year-old actress revealed that she was learning to sing for her upcoming film The Goree Girls where she is playing one of the singers.
When asked by Ellen to practice her singing on the show, Aniston picked I've Got a Crush on You to sing.
"I'm absolutely mortified that you actually did that to me," the Friend star said after finishing. But Ellen said she'd put Aniston into the next round on Idol.
Check out the video of Jennifer Aniston sings I’ve Got A Crush On You below: