Blake Shelton and Reba McEntire Look Back at Season 1 of 'The Voice'

'We look like babies!'

It's Blake Shelton's last season on The Voice, and he's taking it back to where it all began!

The Knockout Rounds kicked off on Monday's all-new episode, and the season 23 Mega Mentor, Reba McEntire, was on hand to complete a full-circle moment for Blake. 

Reba was the Team Blake mentor on the very first season of The Voice, back in April 2011 -- and 12 years later, she's back again and happy to help out her old pal.

"You brought me into this, and now you're taking me out," Blake teased as the pair kicked off the episode.

However, in a rare moment of honest nostalgia, the country star shared what their relationship has meant to him throughout the years, revealing, "Reba was the person that I looked to the most as I was trying to make it in country music."

As for Reba, she was thrilled to be back helping the coaches with their teams and offering tips to the singers who can only hope to have a career half as legendary as her own.

"It's always fun to give advice," she shared, "because I study people when they perform, and I wanna be touched when they're singing to me."

Later in the show, Blake and Reba watched some flashback footage from season 1, recalling the artists they worked with and marveling at how long it's been since the early episodes.

"Look at us, we look like babies!" Reba exclaimed.

ET spoke with the season 23 coaches ahead of the premiere, who all shared how excited they were to be on the show for Blake's final season.

"I texted him," Kelly Clarkson shared. "If he was gonna do a last season, I wanted to make sure I was there."

However, the talk show host insisted that she won't be letting nostalgia affect her competitive nature.

"If [Blake] wins, I am very happy for him, because that is super cool to win on the last season and he's literally the show, from its conception," she conceded. "But, like, I'm not, like, rooting for him to win. I'll be happy for him if he does, but I'm obviously trying to win myself."

The Voice airs Mondays at 8 p.m. PT/ET and Tuesdays at 9 p.m. PT/ET on NBC.