Rossdale will serve as the advisor of "Team Gwen" for The Voice's upcoming "Battle Rounds," but Stefani admitted she "was nervous" to join forces professionally with the Bush frontman, Us Weekly reported in its latest issue.
"We got into a fight the night before," Stefani, 45, told Us. "I was like, 'I don't know about this...' But he's so talented."
Rossdale, 48, will advise Stefani's 12 team members, helping to develop their skill sets and offering encouragement.
The artists on "Team Gwen" are: Mayra Alvarez from La Porte, TX; Anita Antoinette from Kingston, Jamaica and Boston, MA; Sugar Joans from Los Angeles, CA; Jean Kelley from Atlanta, GA; Amanda Lee Peers from Rochester, NY; Jessie Pitts from Birmingham, AL; Troy Ritchie from Trabuco Canyon, CA; Bryana Salaz from San Antonio, TX; Gianna Salvato from Freehold, NJ; Ryan Sill from Sterling, VA; Taylor John Williams from Portland, OR; and Menlik Zergabachew from Silver Spring, MD.
"Pharrell is basically like if Oprah and Yoda had a son. It's unbelievable. He makes everyone cry -- even me!" Stefani told Us, adding that she's such a fan of the show she's "watched every single episode."
During the "Battle Rounds," each coach will pit two of their own team members against one another to perform the same song simultaneously in front of a studio audience. After the vocal battle, the coach must choose which of his/her artists will advance to the "Knockout Rounds," while the losing artist is available to be stolen by another coach. Each coach has two steals available during the "Battle Rounds."
Stefani and Rossdale have three children together -- Kingston, 8; Zuma, 6; and Apollo, seven months.