"She's playing my love interest, so I'm very, very excited about that," Rivera told MTV News.
"We get to sing a song together. It's gonna be good. I'm excited to work with her. We're bringing her to the dark side. Well, she comes in in a Beatles episode, so [we're singing] a Beatles song. I'm excited."
The show is returning for its fifth season this fall. The program is being retooled due to the July drug overdose death of popular cast member Cory Monteith, who played Finn for four seasons.