Season 21 of The Voice premieres in September, and as always, each coach will enlist one high-profile star guest to serve as their team's Battle Rounds advisor. This fall, the Battle Rounds are getting a double dose of country: Jason Aldean will mentor Team Kelly Clarkson, and Dierks Bentley will mentor Team Blake Shelton.

The official announcement came on Monday (Aug. 16), after a teaser clip showed all four The Voice coaches interviewing their Battle Rounds advisors, whose faces were blurred out as they spoke into a voice-distorting microphone.

But some eagle-eyed fans had already guessed that Clarkson's mentor was Aldean, especially because he dropped some hints as to his identity leading up to Monday's announcement. In the teaser clip, for example, Aldean revealed that his nickname was "The Peach" — a reference to his home stage of Georgia — and also said that his proudest accomplishment was winning ACM Entertainer of the Year.

Meanwhile, during his own blurred-out interview with Shelton, Bentley shared musical influences like Keith Whitley, Randy Travis, George Strait and George Jones, making it pretty clear that he was a country act himself. He also revealed that he'd performed on The Voice before, "in 2019, I believe," giving fans an additional hint as to his identity.

After fans dropped their guesses as to which stars were the show's Battle Rounds advisors, The Voice coaches revealed their picks in a follow-up video.

"Hey, you were right, it's Dierks Bentley! Woo!" Shelton crowed excitedly.

"Wow! I'll take what he's drinking," Bentley joked in response, as his face was finally revealed to the camera.

"It's time to introduce who my Battle Advisor is this season ... Jason Aldean!" Clarkson said in her segment.

"Hello, Kelly," Jason replied as his face came into focus, still speaking into the voice-distorting microphone.

Clarkson and Aldean have worked together in the past. Their 2010 duet single, "Don't You Wanna Stay," was a massive country radio hit, becoming Aldean's fifth No. 1 single on the Billboard Hot Country Songs chart and Clarkson's first.

Shelton and Bentley are longtime buddies who own neighboring bars on downtown Nashville's Broadway.

The other two Voice coaches, Ariana Grande and John Legend, also revealed their Battle Advisors picks. Mentoring Team Ariana will be actor and singer Kristin Chenoweth, who has some country leanings of her own: Her 2019 For the Girls album includes guest appearances from Dolly Parton and Reba McEntire. Legend's pick is pop and R&B singer-songwriter Camila Cabello.

Season 21 of The Voice will premiere on Sept. 20. Aside from Grande, who's stepping into a role previously filled by Nick Jonas, all of the coaches are returning to the show after working at least one season previously.

Shelton, the resident country coach, has been on The Voice more than any other celebrity: He's the only coach who has appeared on every single season to date. Team Blake has had eight victories over the course of the show, making him the winningest coach on The Voice, too. His most recent victory came last season, when his team's Cam Anthony took home the top prize.

WATCH: Has The Voice Changed Blake Shelton?

The Voice Stars, Then + Now: