The upcoming season of "The Voice" must be the most studded one yet as international pop and R&B star Rihanna is on board as its key advisor. The announcement was made by NBC executive Bob Greenblatt during the Television Critics' Association press tour last month. 

Rihanna will help "The Voice" coaches Adam Levine, Pharell Williams, Blake Shelton, and Gwen Stefani train their teams during the battle rounds of the singing reality competition. 

Shelton, the resident country music coach of the series, told the Hollywood Life how he enjoyed working with Rihanna this season. 

"Rihanna is hot! She was so great and so funny, so honest which is —  she was really good at that. She really took it seriously and was very good at the job," the chart-topping country singer-songwriter said. 

Shelton also joked about possibly spending more time with the "Diamonds" singer in an interview with Access Hollywood with fellow coach Pharell Williams. 

"I was amazed by Rihanna. She is so funny... and she's crazy about me. We'll probably end up hooking up at some point. I'm just saying," Shelton joked. 

But the country music superstar never fools around during the contest proper, which can be proven by the four-win record in the music competition, including the consecutive wins during seasons 2 to 4. 

Aside from Rihanna, other guest artists will help the coaches this season, including Creedence Clearwater Revival lead singer John Fogerty for Team Adam, country singer Brad Paisley for Team Blake, hip hop star Missy Elliott for Team Pharrell, as well as the young pop star Selena Gomez for Team Gwen. 

Rihanna will join the star-studded roster of past key advisors of "The Voice," including Coldplay's main man Chris Martin, Fun's Nate Ruess, as well as pop superstar Taylor Swift. 

"The Voice" season 9 is slated to premiere on Sept. 21 on NBC.