Watch Blake Shelton's 'Voice' Singers Cover Taylor Swift's 'Anti-Hero' in Battle Rounds Sneak Peek

The Voice airs Mondays at 8 p.m. EST and Tuesdays at 9 p.m. EST on NBC

It's early in The Voice competition, but Blake Shelton is already having to make some tough calls.

In a PEOPLE exclusive preview of Tuesday night's battle rounds, the country star's artists Kylee Dane and Mary Kate Connor are paired up for a duet of Taylor Swift's 2022 hit "Anti-Hero" — and it's so good that Shelton says his heart is "cracking" at the thought of having to choose just one of them to advance to the next round.

"I've been dreading this one — I've told you guys," he says after the performance. "It makes it extra tough because I can see how close you guys have grown together. I'm just proud and excited to have a pairing like you on my last season. From somebody who has done what you're hoping to do, you're going to do this, both of you. You're so good at it."

"Both of you have this singer-songwriter written on your... whatever that is," he says, forgetting the word "bio," which fellow coach Niall Horan helps him remember.

"Is that how you say it in Ireland? Bio?" Shelton, 46, says, as coach Kelly Clarkson suggests he has "another" drink. "OK!" Shelton obliges as he takes a sip from his cup.

Horan, 29, also gave Dane, 19, and Connor, 17, high praise after the performance, saying, "Holy moly!"

"That was honestly one of my favorite ones I've seen," he says. "It's not easy to come out and sing a current song that's huge. People have been listening to the Taylor version since it came out, and then you've made it completely your own."

Horan then says he remembers Dane's audition with Maggie Rogers' "Fallingwater" as "in the same kind of wheelhouse." "It felt like you were very comfortable there," he says.

As for Connor, he says, "there was a great part where you sung in unison and then you split off and you were piercing through. It gave me little goosebumps to be honest. Blakey boy, you got one hell of a choice here."

Ultimately, though, Horan says "I would probably lean towards Mary Kate just cause of that feeling I got when she pierced through on the break of the harmonies."

RELATED VIDEO: Blake Shelton Wants to Start a Band Called 'Different Directions' with Niall Horan and Their Fellow 'Voice' Coaches

Coach Chance the Rapper, 29, agrees that the duo's harmonies were impressive, saying, "It seems like y'all grew up together or something, because it was so in sync."

"The harmonies meshed so well — y'all should record a cover or something of it," he says. "It was so dope. It was super ill. I think the whole point of this show is to emphasize your identity through your voice. If I were you Blake, I would go with Kylee. I think Kylee had a sense of control and a sense of self that this competition needs and could win the whole competition for you. But also, that's just my advice."

"I respect your advice. I love it," Shelton says to that, before looking at Clarkson, 40, and saying, "I gotta listen to her now, though."

After some laughs from the audience, Clarkson says, "It was so evenly matched, guys."

"Kylee, your voice, it has this thing that singers get jealous of," she says. "No matter what you sing, it's always going to sound special. You just have that kind of style about you. Mary Kate, you have this passion that's breathtakingly beautiful."

The winner of the battle round will be revealed during Tuesday's episode airing at 9 p.m. EST on NBC. The Voice airs Mondays at 8 p.m. EST and Tuesdays at 9 p.m. EST on NBC.